Alignment layer, process for producing alignment layer, substrate with alignment layer and liquid crystal dispaly

ABSTRACT

The present invention has a main object to provide an orientation film that enables appropriately orienting the liquid crystal without forming a structural member such as a projecting portion, etc. or without performing rubbing processing. To attain the object, the present invention provides an orientation film that has on its surface on a side where the liquid crystal layer is contacted therewith a pattern including a water-repellent region and a hydrophilic region that is a region where the angle of contact with water is smaller than that in the water-repellent region.

TECHNICAL FIELD

The present invention relates to an orientation film that can orient aliquid crystal molecule to a direction which is suitable with respect toa relevant substrate and that is advantageous in terms of the cost and,more particularly, to an orientation film that enables, for improvingthe field-of-view characteristic, easily dividing the orientationdirection within a relevant pixel, a substrate equipped with theorientation film, and a liquid crystal display device that uses theorientation film-equipped substrate.

BACKGROUND ART

A liquid crystal cell is a display device that utilizes theelectro-optical change of the liquid crystal. It is small in size andlight in weight, as the device, and is small in power consumption, andthe like. Attention has in recent years been drawn toward thosecharacteristics of the liquid crystal cell, and it has been making aremarkable expansion and development as a display device for use asvarious kinds of displays. Among all, a twisted nematic type (TN type)field effect type liquid crystal cell that uses nematic liquid crystalhaving a positive dielectric-anisotropic property as well as a pair ofelectrode substrates that oppose each other is a typical one of theliquid crystal cell. Namely, in it, so-called “homogeneous orientation”is made of the liquid crystal molecule in the way that at each interfacethat molecule is oriented in parallel with the substrate. Further, theboth substrates are combined with each other so that the directions inwhich the liquid crystal molecules are oriented may intersect each otherat a right angle.

On the other hand, in a case of using a nematic liquid crystal havingnegative dielectric anisotropic property, many field effect type liquidcrystal cells are known. They include a field-controlled birefringencetype (ECB type) wherein so-called “homeo-tropic” orientation is made ofthe liquid crystal molecule in the way that at each interface of a pairof electrode substrates that oppose each other it is orientedperpendicularly to the substrate and which thereby utilizes a change inthe birefringence in the liquid crystal layer that occurs when a voltagehas been applied, a phase-transition type (PC type) which utilizes achange in the phase structure of the liquid crystal, and a guest/hosttype (GH type) in which coloring matter is mixed.

A brief explanation will now be given, using FIG. 1, of theabove-described liquid crystal display device in vertical orientationmode. This vertical orientation mode is the one in which negative typeliquid-crystalline material having negative dielectric constantanisotropy and an orientation film in the vertical direction arecombined with each other. In that mode, as illustrated in FIG. 1A, whenno voltage is applied, the liquid crystal molecule is oriented in thevertical direction, thereby a black display is given. As illustrated inFIG. 1C, when a prescribed level of voltage is applied, the liquidcrystal molecule is oriented in the horizontal direction, thereby awhite display is given. This vertical orientation mode has a merit inthat, compared with the TN mode, contrast of the display is high and, inaddition, black/white level response speed also is high.

However, in a case where a half tone display is made in the verticalorientation mode, a problem arises in that the dependency on the viewingangle of the displayed state occurs. Namely, while, in a case where ahalf tone is displayed in the vertical orientation mode, a lower levelof voltage than at the time when a white color is displayed is applied,in this case as illustrated in FIG. 1B, the liquid crystal moleculebecomes oriented in an oblique direction. In that case, as illustrated,with respect to a light that advances from the right/lower to theleft/upper, the liquid crystal molecule becomes oriented in parallel.Accordingly, it results that because of the liquid crystal's exhibitingalmost no birefringence effect, when viewing from the left side, theliquid crystal looks black. In contrast to this, with respect to a lightthat advances from the left/lower to the right/upper, the liquid crystalmolecule is oriented perpendicularly. Therefore, the liquid crystalexhibits a great birefringence effect upon the incident light, thereby adisplay that is near to white is made. Like that, the verticalorientation mode had the problem that the dependency on the viewingangle of the displayed state occurred.

For solving the above-described problem, it is known that the viewingangle characteristic is improved by dividing the orientation directionof the liquid crystal molecule into a plurality of different directionswithin the pixel. Japanese Patent Application Laid-Open No. 6-301036discloses a liquid crystal display device in vertical orientation mode,in which an opening portion is formed in each of the mutually opposingportions at the centers of the pixel electrodes of the opposingelectrodes; the portions where the electric field is inclined are formedat the central parts of the pixels; and the direction in which theliquid crystal molecule is oriented is thereby divided into two, or,four, directions. However, the liquid crystal display device that isdisclosed in Japanese Patent Application Laid-Open No. 6-301036 involvestherein a problem that the response speed is slow. Further, it hasturned out to be the case that, especially, the response speed is low atthe time when a transition is made from a state where no voltage isapplied to a state where a voltage is applied. It is thought that thisis because the length of a region being formed within the pixel wherethe directions in which the liquid crystal molecules are oriented arethe same is approximately half the length of the pixel, and, because,therefore, a significantly large length of time is needed until theorientation of all the liquid crystal molecules within the region is putin regular order.

On the other hand, Japanese Patent Application Laid-Open No. 7-199193discloses the following liquid crystal display device in verticalorientation mode. In that device, by providing on the electrode inclinedsurfaces the inclined surfaces directions of which are different, thedirection in which the liquid crystal molecule is oriented within thepixel is differentiated or divided into a plurality of directions.However, in the disclosed construction, since the inclined surfaces areprovided on the entire pixel, when no voltage is applied, the liquidcrystal contacting every orientation surface is oriented along theinclined surface. Therefore, it is impossible to obtain a completedisplay of black, with the result that the problem that the contrastbecomes lowered occurred. In addition, since the inclined surfaces areprovided over the entire pixel, it turned out to be the case that theinclined surface is gentle and this cannot be said enough to define theorientation direction of the liquid crystal. For making the inclinedsurface sharper, it is necessary to make the relevant structure greaterin thickness. However, making the relevant structure of the dielectricgreater in thickness results in that during the operation of the deviceelectric charge is accumulated on the structure. It has turned out to bethe case that the results in the phenomenon's called “seizure” occurringthat due to the electric charge that has been accumulated thereon thedirection of the liquid crystal molecule is not changed even when avoltage is applied between the electrodes.

Further, as means for solving the above-described point in problem,there is disclosed in Japanese Patent-Inserted Official Gazette No.2947350 a technique for forming a projecting portion on the substrate asdomain regulating means. FIGS. 2A to 2C are views illustrating theprinciple that is relevant thereto. As illustrated in FIG. 2A, in astate where no voltage is applied, the liquid crystal molecule isoriented in a direction vertical to the surface of the substrate.Applying an intermediate voltage results in that, as illustrated in FIG.2B, at the electrode slit portion (electrode edge portion), an electricfield that is inclined with respect to the surface of the substrateoccurs. Also, the liquid crystal molecule at the projecting portion 20is slightly inclined from that in a state where no voltage is applied.Due to the inclined surface of the projecting portion as well as theelectric field that occurs slantwise, the direction in which the liquidcrystal molecule is inclined is determined. Thereby, at the positionjust central between the projecting portion 20 and the electrode slit,the direction in which the liquid crystal molecule is oriented isdivided into a plurality of directions. At this time, a light thattransmits, for example, from just below to just above is somewhataffected by birefringence and that transmission is suppressed becausethe liquid crystal molecule is somewhat inclined. As a result of this, ahalf tone of gray display is obtained. In a region where the liquidcrystal molecule is inclined leftward, a light that transmits from rightlower to left upper has the difficulty of transmitting, and, in a regionwhere the liquid crystal molecule is inclined rightward, is very easy totransmit. Therefore, when averaged, a half tone of gray display isobtained. According to the same principle, a light that transmits fromleft lower to right upper, also, enables a display of gray. Namely, auniform level of display is obtained in omni-direction. Further, when aprescribed voltage is applied, the liquid crystal molecule becomes laidhorizontal, whereby a display of white is obtained. Accordingly, in allstates of display that include a state's of black being displayed, astate's of half tone being displayed, and a state's of white beingdisplayed, excellent display that has less dependency on the viewingangle is obtained. The official gazette referred to above describes likethat.

However, the above-described method necessitates forming the structuralmember of “projecting portion” on the liquid crystal substrate and,therefore, has various points in problem such as making themanufacturing process complex, increasing the cost, and decreasing theyield.

DISCLOSURE OF INVENTION

The present invention has been made in view of the above-describedpoints in problem and has a main object to provide an orientation filmthat enables the liquid-crystalline molecule to be appropriatelyoriented without forming a structural member of “projecting portion”such as that described above and, in addition, without performingrubbing.

To attain the above object, the present invention provides anorientation film which comprises a pattern, on its surface of a sidewhere a liquid crystal layer is contacted, that includes awater-repellent region and a hydrophilic region that is a region wherethe angle of contact with water is smaller than that in thewater-repellent region. By forming the hydrophilic region, within thewater-repellent region, into a pattern configuration in theabove-described way, for example in a liquid crystal display device invertical orientation mode, it becomes possible, by utilizing the naturethat the liquid crystal molecule that is vertically oriented in thewater-repellent region is inclined within the hydrophilic region, toperform orientation division, within a relevant pixel, of the liquidcrystal molecule that has been vertically oriented. Accordingly, byusing that orientation film, it is possible to easily perform theorientation division within the pixel and to make the liquid crystaldisplay device the one having less dependency on the viewing anglethrough the same action as that which occurs when having formed theprojecting portion that was stated before.

In the present invention, preferably, the angle of contact with water inthe water-repellent region is greater by an angle falling within a rangeof from 10° to 120° than that in the hydrophilic region. This isbecause, by making the difference in wettability between thewater-repellent region and the hydrophilic region the one thatcorresponds to the range, it is possible to more effectively performorientation within the pixel of the liquid crystal molecule.

Also, in the present invention, it is preferable that the angle ofcontact with water in the water-repellent region falls within a range offrom 40° to 120°. This is because, in a case of using the orientationfilm in, for example, the liquid crystal display device in verticalorientation mode, in order to vertically orient the liquid crystalmolecule within the water-repellent region, it is preferable that theorientation film has a water repellency that is to an extent describedabove.

Also, in the present invention, the orientation film comprises acompound that has polyimide, polyamide, or organopolysiloxane as theprincipal chain and has as the side chain linear alkyl group, orfluorine-containing alkyl group, the number of carbons of which is from4 to 22 inclusive; and the density of the side chains in thewater-repellent region is lower than that of the side chains in thehydrophilic region.

As described above, the present invention is based on the utilization ofthe nature that the liquid crystal molecule in the water-repellentregion is vertically oriented and that in the hydrophilic molecule isinclined. However, if, for example, using the orientation film in theliquid crystal display device in vertical orientation mode, furtherusing the orientation film having formed on its surface side chains forvertically orienting the liquid crystal molecule is preferable forenhancing the orientation property of the liquid crystal molecule. Fromthis point of view, the orientation film that comprises the compounddescribed above is preferable. Further, from the point of view that inthe hydrophilic region the liquid crystal molecule preferably isinclined in that region, it is preferable that the density of the sidechains be lower in the hydrophilic region than in the water-repellentregion.

In the water-repellent region, preferably, the weight of the side chainsis 5% by weight or more based upon the total weight of the relevantmaterial (orientation film material). This is because, if having theside chains that are to that extent, the orientation film comes to havean orientation property that is sufficient as the orientation film.

In the present invention, preferably, the organopolysiloxane ispolysiloxane that contains therein a fluoroalkyl group and is the onethat is a hydrolytic condensate or co-hydrolytic condensate of one, ortwo or more, kinds of silicon compounds each of which is expressed byY_(n)SiX_((4-n)) (where Y represents an alkyl group, fluoroalkyl group,vinyl group, amino group, phenyl group, or epoxy group; X represents analkoxyl group or halogen; and n represents an integer of from 0 to 3inclusive.). The reason for this is as follows. By, using theorganopolysiloxane that is like that, performing treatment with the useof a photocatalyst-containing layer substrate that will later bedescribed, it is possible to relatively easily create the hydrophilicregion in the water-repellent region and to make greater the differencein wettability between the water-repellent region and the hydrophilicregion. Therefore, this material is suitable for causing orientationwithin the pixel of the liquid crystal molecule.

Also, in the present invention, preferably, the polyimide is the onethat is prepared by causing reaction and polymerization of at least atetracarboxylic acid component and a diamine component containing alinear alkyl group and thereby making this material a polyimideprecursor containing therein a linear alkyl group and imidizing theprecursor. The reason for this is as follows. The polyimide is the onethat has hitherto been used as the orientation film and, when formingthe orientation film using the material, the possibility is very lowthat the inconvenience will arise.

Also, the present invention provides a method of manufacturing anorientation film, which comprises an orientation film-forming processfor forming an orientation film on a substrate, and a pattern-formingprocess for forming with respect to the surface of the orientation filma pattern including a water-repellent region and a hydrophilic regionthat is a region where the angle of contact with water is smaller thanthat in the water-repellent region.

In the present invention, since, only by forming the wettability patternincluding the water-repellent region and the hydrophilic region on theorientation film in the above-described way, it is possible to orientwithin the pixel, there exists a merit of enabling more easilymanufacturing than by using a method of, for example, forming astructural member such as a projecting portion.

Also, in the present invention, preferably, the orientation film formedon the substrate is a change-in-wettability layer the wettability onwhose surface changes due to the action of photocatalyst; and thepattern-forming process comprises:

-   -   a photocatalyst-containing layer side substrate-preparing        process for preparing a photocatalyst-containing layer side        substrate that has a photocatalyst-containing layer containing        therein photocatalyst and a base material member; and    -   a photocatalyst-treating process for, after disposing the        photocatalyst-containing layer and the change-in-wettability        layer in the way that the gap therebetween becomes 200 μm or        less, radiating light energy from a prescribed direction onto        the resulting mass to thereby form a pattern, including a        hydrophilic region and a water-repellent region, with respect to        the surface of the change-in-wettability layer.

The reason for this is as follows. Namely, only by using thechange-in-wettability and disposing the photocatalyst-containing layerin the way that a prescribed gap exists between the two layers andthereafter radiating light energy in the above-described way, it ispossible to form the change-in-wettability layer, i.e. a pattern on theorientation film where the wettability in each region is different.Therefore, the wettability pattern can be very easily formed on theorientation film and it is possible to easily form the orientation filmwherein the orientation within the pixel is excellent.

In the present invention, preferably, the photocatalyst-containing layerside substrate comprises a base material member and aphotocatalyst-containing layer that has formed, on the substrate, into apattern configuration. This is because, by forming thephotocatalyst-containing layer into a pattern configuration like that,it becomes possible to form on the change-in-wettability layer a patternincluding the water-repellent region and the hydrophilic region, whichare different from each other in terms of the wettability, without usingany photo-mask. In addition, since only the surface of contact with thephotocatalyst-containing layer changes into the hydrophilic region, theenergy that is to be radiated is not particularly limited to parallelrays of energy and, also, the radiation direction of the energy is notparticularly limited. Therefore, there exists a merit that the kinds ofenergy sources and the degree of freedom in which they are disposedgreatly increase.

Also, the photocatalyst-containing layer side substrate that is preparedin the photocatalyst-containing layer side substrate-preparing processcomprises a base material member, a photocatalyst-containing layerformed on the substrate, and a photocatalyst-containing layer sidelight-shielding portion formed into a pattern configuration; and theradiation of the energy in the pattern-forming process may be performedfrom the photocatalyst-containing layer side substrate.

By the photocatalyst-containing layer side substrate's having thephotocatalyst-containing layer side light-shielding portion in that way,there is no necessity of using a photo-mask, etc. when performingexposure, which eliminates the necessity of performing positionalalignment, etc. with the photo-mask. Resultantly, it becomes possible tosimplify the relevant process.

Further, in the photocatalyst-containing layer side substrate, thephotocatalyst-containing layer side light-shielding portion may beformed into a pattern configuration on the base material member; and,further, on the light-shielding portion, there may be formed thephotocatalyst-containing layer. Also, in the photocatalyst-containinglayer side substrate, the photocatalyst-containing layer may be formedon the base material member and, on this photocatalyst-containing layer,the photocatalyst-containing layer sidelight-shielding portion may beformed into a pattern configuration.

It can be said preferable that the photocatalyst-containing layer sidelight-shielding portion is disposed at a position that is near to theposition of contact with the change-in-wettability layer in terms of theaccuracy of the wettability pattern obtained. Therefore, it ispreferable to dispose the photocatalyst-containing layer sidelight-shielding portion at the position. Also, in a case of forming thephotocatalyst-containing layer side light-shielding portion on thephotocatalyst-containing layer, there exists a merit that thephotocatalyst-containing layer side light-shielding portion can be usedas a spacer when disposing the photocatalyst-containing layer and thechange-in-wettability layer in the wettability pattern-forming processwith a gap intervening in between.

In the present invention, preferably, the photocatalyst-containing layeris a layer that consists of photocatalyst. The reason for this is asfollows. If the photocatalyst-containing layer is a layer that consistsof only photocatalyst, it is possible to enhance the efficiency ofchanging the wettability of the change-in-wettability layer. It istherefore possible to form a wettability pattern on the surface of theorientation film with a high efficiency.

Also, in the present invention, preferably, the photocatalyst-containinglayer is a layer that is prepared by forming photocatalyst onto the basematerial member, as a film, by a vacuum film-making technique. Thereason for this is as follows. By forming the photocatalyst-containinglayer by the vacuum filmmaking technique in the above-described way, itbecomes possible to make the layer the one the surface of which has lessunevenness and the thickness of which is uniform and which ishomogeneous and, further, it becomes possible to uniformly and highlyefficiently form the wettability pattern with respect to the surface ofthe change-in-wettability layer.

Also, the photocatalyst-containing layer may be a layer that hasphotocatalyst and a binder. The reason for this is as follows. By usinga binder like that, it becomes possible to relatively easily form thephotocatalyst-containing layer and, as a result, to manufacture apattern formation at a low cost.

Further, the present invention provides an orientation film-equippedsubstrate which comprises a substrate, and an orientation film that isformed on the substrate and that has on its surface on a side where aliquid crystal layer is contacted therewith a pattern including awater-repellent region and a hydrophilic region that is a region wherethe angle of contact with water is smaller than that in thewater-repellent region. By the substrate's having the orientation filmhaving formed in its water-repellent region the hydrophilic region inthe configuration of a pattern in the above-described way, in a case ofusing the substrate in the liquid crystal display device in, forexample, vertical orientation mode, it becomes possible, by utilizingthe nature that the liquid crystal molecule that is vertically orientedin the water-repellent region gets inclined in the hydrophilic region,to cause orientation/division within a relevant pixel of the liquidcrystal molecule that has vertically been oriented.

Also, in the present invention, the orientation film-equipped substratemay be the one wherein the liquid crystal layer is disposed on a sidewhere the surface of the orientation film is located, or may be the onethat has formed on its surface a colored layer; and on the surface ofthe colored layer there is formed a transparent electrode layer; and onthe transparent electrode layer there is formed the orientation film.

Further, also, the present invention provides a liquid crystal displaydevice which comprises:

-   -   a color filter side substrate that has a first substrate, a        colored layer that is formed on the first substrate, a        transparent electrode layer formed on the colored layer, and an        orientation film that is formed on the transparent electrode        layer and that has on its surface on a side where a liquid        crystal layer is contacted therewith a pattern including a        water-repellent region and a hydrophilic region that is a region        where the angle of contact with water is smaller than that in        the water-repellent region, and    -   an opposing substrate that has a second substrate, a transparent        electrode layer formed on the second substrate, and an        orientation film that is formed on the surface of the        transparent electrode layer and that has on its surface on a        side where a liquid crystal layer is contacted therewith a        pattern including a water-repellent region and a hydrophilic        region that is a region where the angle of contact with water is        smaller than that in the water-repellent region,    -   whereby the orientation film of the color filter side substrate        and the orientation film of the opposing substrate are disposed        in the way they oppose each other; and    -   liquid crystal is sealed into between the two orientation films.

The liquid crystal display device is the one that has an orientationfilm having formed within its water-repellent region in the form of apattern the hydrophilic region. Therefore, for example, in the liquidcrystal display device in vertical orientation mode, by utilizing thenature that the liquid crystal molecule that is vertically oriented inthe water-repellent region gets inclined in the hydrophilic region, itis possible to cause orientation/division within the pixel of the liquidcrystal molecule that has been vertically oriented.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory view illustrating a liquid crystal displaydevice in vertical orientation mode;

FIG. 2 is an explanatory view illustrating a conventional example of aliquid crystal display device in vertical orientation mode within apixel of that the orientation-direction differentiation (division) ismade;

FIG. 3 is a plan view illustrating a hydrophilic pattern that is used inthe orientation film used in an MVA mode;

FIG. 4 is a plan view illustrating an example wherein aliquid-crystalline molecule is disposed on the hydrophilic patternillustrated in FIG. 3;

FIG. 5 is a schematic sectional view illustrating a state where theexample illustrated in FIG. 4 is viewed from a section thereof;

FIG. 6 is a plan view illustrating a hydrophilic pattern that is used inthe orientation film used in an IPS mode;

FIG. 7 is a plan view illustrating an example wherein aliquid-crystalline molecule is disposed on the hydrophilic patternillustrated in FIG. 6;

FIG. 8 is a schematic sectional view illustrating a state where theexample illustrated in FIG. 7 is viewed from a section thereof;

FIG. 9 is a plan view illustrating a hydrophilic pattern that is used inthe orientation film used in a TN mode;

FIG. 10 is a plan view illustrating an example wherein aliquid-crystalline molecule is disposed on the hydrophilic patternillustrated in FIG. 9;

FIG. 11 is a schematic sectional view illustrating a state where theexample illustrated in FIG. 10 is viewed from a section thereof;

FIG. 12 is a schematic sectional view illustrating an example of aphotocatalyst-containing layer side substrate that is used in thepresent invention;

FIG. 13 is a schematic sectional view illustrating another example ofthe photocatalyst-containing layer side substrate that is used in thepresent invention;

FIG. 14 is a schematic sectional view illustrating still another exampleof the photocatalyst-containing layer side substrate that is used in thepresent invention;

FIG. 15 is a schematic sectional view illustrating a further example ofthe photocatalyst-containing layer side substrate that is used in thepresent invention;

FIG. 16 is a schematic sectional view illustrating an example of anorientation film-equipped substrate according to the present invention;

FIG. 17 is a schematic sectional view illustrating another example ofthe orientation film-equipped substrate according to the presentinvention;

FIG. 18 is a schematic sectional view illustrating still another exampleof an orientation film-equipped substrate according to the presentinvention;

FIG. 19 is a schematic sectional view illustrating an example of aliquid crystal display device according to the present invention; and

FIG. 20 is a schematic sectional view illustrating a verticalorientation mode of liquid crystal display device that includes anorientation film according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be concretely explained. Thepresent invention includes an orientation film, a method ofmanufacturing the orientation film, an orientation film-equippedsubstrate, and a liquid crystal display device. Hereinafter, each ofthese will be explained, individually, under its relevant item.

A. Orientation Film

An orientation film according to the present invention is characterizedby having on the surface thereof that is located on a side where aliquid crystal layer is contacted therewith a pattern that includes awater-repellent region and a hydrophilic region where the angle ofcontact with water is smaller than that in the water-repellent region.

In the present invention, by that surface's of the orientation filmbeing defined as being the water-repellent region and by the pattern'sof hydrophilic region being formed within the water-repellent region inthe above-described way, it becomes possible to perform orientation indirection of the liquid crystal molecule within a relevant pixel. Thereason for this is as follows.

Namely, in, for example, a liquid crystal display device in verticalorientation mode (hereinafter also referred to as “MVA mode” as theoccasion demands), on the surface having water repellency, of theorientation film that is located within a region forming the relevantpixel, a prescribed pattern of hydrophilic region is formed. Regardingthe liquid-crystalline molecule, although in terms of its nature it isvertically oriented within the water-repellent region, it is slightlyobliquely oriented within the hydrophilic region. Accordingly, byadjusting the degree of wettability, configuration, etc. of thishydrophilic region, it becomes possible to control the orientationdirection of the liquid-crystalline molecule in the same pixel so thatit may be differentiated, or divided, into two, or four, differentdirections. Accordingly, by using the orientation film formed like that,it is possible to provide a liquid crystal display device that has lessdependency on the viewing angle.

Also, in a case where the liquid crystal molecule is arrayed in parallelwith the substrate as in an IPS mode, the TN mode, etc., since theliquid crystal molecule is oriented along the pattern of hydrophilicregion, forming a pattern of hydrophilic region shaped like a stripeenables orienting the liquid crystal molecule. In the present invention,there is the merit that, by using the technique, it is possible to forman orientation layer without executing a rubbing process that hashitherto been carried out.

(Water-Repellent Region and Hydrophilic Region)

The orientation film according to the present invention is characterizedby having formed on the surface thereof that is on a side where theliquid crystal layer is contacted therewith as described above, apattern including the water-repellent region and the hydrophilic region.This hydrophilic region is not particularly limited only if it is aregion where the angle of contact with water is smaller than that in thewater-repellent region. The wettability within the hydrophilic regionmay be uniform or non-uniform.

Also, the difference in wettability between this region and thewater-repellent region is not limited in particular. However, from thestandpoint of the easiness with which the orientation direction iscontrolled, etc., it is preferable that the difference between the angleof contact with water in the water-repellent region and that in thehydrophilic region falls within a range of from 10° to 120°, especiallya range of from 60° to 120°.

For the material using which the hydrophilic region and thewater-repellent region are formed, ordinarily, the same material isused, and, preferably, by performing surface treatment of the surfacethereof that utilizes a photocatalyst-containing layer, etc. as laterdescribed, the difference in terms of the wettability is caused tooccur. However, the present invention is not particularly limitedthereto, and a different material may be used between for forming thehydrophilic region and for forming the water-repellent region.

The pattern configuration of the hydrophilic region within the regionwhere the relevant pixel is formed can be various depending on the typeof a liquid crystal display device having used therein an orientationfilm.

For instance, in the liquid crystal display device in MVA mode, anypattern is available only if it is a type that, within the pixelthereof, is able to divide and control the orientation direction of theliquid crystal molecule. The pattern is different depending on thedifference in wettability between the hydrophilic region and thewater-repellent region, the kind of the liquid-crystalline molecule,etc. Namely, it is appropriately determined according to the respectiveconditions that are relevant thereto.

Concretely, a pattern where, as illustrated in FIG. 3, the hydrophilicregion is arrayed in the form of a wedge can be taken up as an example.If the pattern is like that, the liquid crystal molecule that isvertically disposed in a state of no electric field's being appliedbecomes oriented along the wedge type pattern as a result of an electricfield's being applied, as illustrated in FIG. 4. Therefore, it becomespossible, within the same pixel, to control the orientation direction ofthe liquid-crystalline molecule so that the direction may become fourdifferent directions. Thereby, the liquid crystal display device can bemade the one having less dependency on the viewing angle. The pattern ofhydrophilic region, preferably, is formed, as a pattern, on eithersubstrate of both the color filer side substrate and the opposing sidesubstrate. Incidentally, FIG. 5 illustrates a state where the liquidcrystal molecule is viewed from a section thereof.

Also, in the liquid crystal display device in IPS mode, as illustratedin FIG. 6, the hydrophilic region is patterned like a stripe. In thiscase, for example, on either substrate of an upper substrate that is thecolor filter side substrate and a lower substrate that is the opposingsubstrate, the pattern is formed in parallel with another one that isadjacent thereto. By the stripe pattern's of hydrophilic region beingformed in parallel on either substrate of the upper substrate and lowersubstrate in that way, as illustrated in FIG. 7, when no electric fieldis being applied, the liquid crystal molecule is brought to a state ofits being oriented in parallel with the hydrophilic region. Also, whenan electric field is applied, the liquid crystal region becomes orientedin a direction that intersects the stripe pattern of hydrophilic region.Incidentally, FIG. 8 illustrates a state that appears when the liquidcrystal molecule is viewed from a section.

By forming the hydrophilic region into a configuration of stripe in theabove-described way, it becomes possible to orient theliquid-crystalline molecule without executing relevant rubbing processwith respect to the orientation film.

Further, in the liquid crystal display device in TN mode, although, asillustrated in FIG. 9, the hydrophilic region is patterned in the formof a stripe, in the case of the TN mode, the stripe is formed, forexample, in the way that the stripe on an upper substrate that is thecolor filter side substrate and that on a lower substrate that is theopposing substrate intersect each other at a right angle. By the stripepattern's being formed in the way that the stripe pattern of hydrophilicregion on the upper substrate and that on the lower substrate intersecteach other at a right angle in the above-described way, the liquidcrystal molecule becomes oriented, when no electric field is beingapplied, into a state of its being twisted 90 degrees from the lowersubstrate toward the upper substrate, as illustrated in FIG. 10. Also,when an electric field is applied, the liquid crystal molecule isoriented vertically, or perpendicularly, to the substrate. This state isillustrated in FIG. 11 that illustrates a state that appears when theliquid crystal molecule is viewed from a section.

In this case as well, it is possible to use the orientation film as theone able to orient the liquid crystal molecule, without performingrubbing of the orientation film.

Also, the area ratio between the hydrophilic region and thewater-repellent region within the region where the pixel is formed,also, greatly differs according to the type, the conditions, etc. theliquid crystal display device used, as in the case of theabove-described configuration of the pattern of hydrophilic region.However, from the standpoint that in a case where the hydrophilic regionis excessively large, the control ordinarily becomes difficult, etc.,under the assumption that the region where the pixel is formed be 100%,the hydrophilic region is formed within a range of from 0.1% to 90%,especially a range of from 0.1% to 50%.

On the other hand, the water-repellent region is ordinarily the one,such as that described above, where surface treatment that uses aphotocatalyst-containing layer, etc. is not performed. However, thepresent invention is not limited thereto. For instance, the pattern ofwater-repellent region may be the one that has been obtained byperforming surface treatment with respect to the originalwater-repellent region.

This water-repellent region is not particularly limited only if it isthe region where the angle of contact with water is greater than that inthe hydrophilic region. However, in order to vertically orient theliquid crystal molecule, it is preferable that the water-repellentregion has a prescribed level of water repellency. From that viewpoint,in the present invention, the angle of contact with water in thewater-repellent region, preferably, is set to fall within a range offrom 40° to 120°, especially a range of from 70° to 120°.

Incidentally, the “angle of contact with water” in the present inventionis an angular value that is obtained by measuring the angle of contactwith water (in 30 sec. after dropping liquid droplets from themicro-syringe) by using an angle of contact measuring instrument (CA-Ztype made by Kyowa Interface Science Inc.).

(Material for Orientation Film)

The orientation film according to the present invention does not have amaterial therefor not particularly limited if it has the above-describedwater-repellent region and hydrophilic property. However, ahigh-molecular material having a prescribed side chain is suitably usedfor the following reasons.

First, as later described, in the present invention, it is preferable toform a pattern of hydrophilic region by performing surface treatmentwith respect to the surface of the water-repellent region by using aphotocatalyst-containing layer. However, when, in the surface treatmentusing a photocatalyst-containing layer, a relevant material has, forexample, an alkyl group or fluorine-containing alkyl group as the sidechain, the difference in wettability between the both regions is easierto appear when the surface treatment has been performed. Therefore, therelevant material is preferable in that respect.

Also, as another reason for that, the following can be said. Namely,although in the water-repellent region according to the presentinvention, it is preferable that the liquid crystal molecule bevertically oriented, in a case where the relevant material has inaddition to its orientation film's having water repellency a prescribednumber of chains and rubbing processing is performed with respectthereto, the liquid crystal molecule becomes able to be more effectivelyoriented.

Although the side chain is not particularly limited, normal alkyl groupor fluorine-containing alkyl group the number of carbons of which fallswithin a range of from 40 to 22, preferably from 50 to 10 can be takenup as the example.

Also, in the present invention, it is preferable that, in thewater-repellent region, the side chain be the one wherein the weightthereof is 5% by weight or more based upon the total weight. The reasonfor this is that, if the density of the side chain is to that extent,the water-repellent region can sufficiently exhibit the ability toorient the liquid-crystalline molecule.

On the other hand, although the principal chain that has theabove-described side chain is not particularly limited, it preferably ispolyimide-, polyamide-, or polysiloxane-based principal chain material.

Hereinafter, an explanation will be given of those materials that arepreferable for use as the orientation film under separate items ofpolyimide-based, polyamide-base, and polysiloxane-based, material.

a. Polyimide-Based

Polyimide resin that is used as the material for the orientation filmaccording to the present invention, preferably, is the one the polyimideof which is the one that is prepared by causing reaction andpolymerization of at least a tetracarboxylic acid component and adiamine component containing therein a linear alkyl group and making theresulting material a polyimide precursor containing therein a linearalkyl group and imidizing the precursor.

In the present invention, as that polyimide, there can be used polyimidethat is disclosed in, for example, Japanese Patent Application Laid-OpenNo. 6-3678. Namely, the polyimide containing therein a linear alkylgroup is polyimide that is prepared by causing reaction andpolymerization between a tetracarboxylic acid component and a diaminecomponent not containing therein a linear alkyl group and/or a diaminecomponent containing therein a linear alkyl group and/or a monoaminecontaining therein a linear alkyl group and/or a dicarboxlylic acidcomponent containing therein a linear alkyl group, and thereby makingthe resulting material a polyimide precursor containing therein a linearalkyl group, and imidizing the precursor.

More specifically, a material that is obtained by mixing a diimidecompound containing therein a linear alkyl group with respect topolyimide not containing therein a linear alkyl group may be used, and,asthepolyimide side chain, polyimide containing therein a linear alkylgroup. A material that is obtained by causing reaction of a linear alkylgroup with respect to the molecular chain terminal of polyimide notcontaining therein a linear alkyl group may be used. However, in orderto obtain stable vertical orientation that is intended to be achieved bythe present invention, the material must be the one the carbons numberof whole linear alkyl group is 12 or more and the content of that, whencalculated in terms of the weight of the alkyl group, is 5% or morebased upon the total weight of polyimide.

The tetracarboxylic acid component that is used to obtain polyimide usedin the present invention is not particularly limited. As the concreteexamples, it includes aromatic carboxylic acids, such as pyromelliticacid, 2,3,6,7-naphthalene tetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalene tetracarboxylic acid,2,3,6,7-anthracene tetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3′,4,4′-biphenyl tetracarboxylic acid,2,3,3′,4-biphenyl tetracarboxylic acid, bis(3,4-dicarboxylphenyl)ether,3,3′,4,4′-benzophenone tetracarboxylic acid,bis(3,4-dicarboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)methane,2,2-bis(3,4-dicarboxyphenyl)propane,1,1,1,3,3,3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl)propane,bis(3,4-dicarboxyphenyl)dimethyl silane,bis(3,4-dicarboxyphenyl)diphenyl silane, 2,3,4,5-pyridinetetracarboxylic acid, or 2,6-bis(3,4-dicarboxyphenyl)pyridine,dianhydrides thereof, and dicarboxylic acid diacid halides thereof,cycloaliphatic tetracarboxylic acids, such as 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentane tetracarboxylic acid,1,2,4,5-cyclohexane tetracarboxylic acid, 2,3,5-tricarboxy cyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinicacid, dianhydrides thereof, and dicarboxylic acid diacid halidesthereof, and aliphatic tetracarboxylic acids, such as 1,2,3,4-butanetetracarboxylic acid, dianhydrides thereof, and dicarboxylic acid diacidhalides thereof.

Especially, from the viewpoint of the transparency of the coating film,cycloaliphatic tetracarboxylic acids, dianhydrides thereof, anddicarboxylic acid diacid halides thereof are preferable. Further,1,2,3,4-cyclobutane tetracarboxylic acid dianhydrides are preferable.Also, tetracarboxylic acid thereof and one, or two or more, kinds ofderivatives thereof can also be used in a form where they are mixedtogether.

The diamine component that does not contain a linear alkyl group, whichis used to obtain polyimide used in the present invention, is a diaminethat is generally used to synthesize polyimide, and that is notparticularly limited.

The diamine includes, for example, aromatic diamines, such asp-phenylene diamine, m-phenylene diamine, 2,5-diaminotoluene,2,6-diamino toluene, 4,4′-diamino biphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diamino biphenyl, diamino diphenylmethane, diamino diphenyl ether, 2,2-diamino diphenyl propane,bis(3,5-diethyl-4-amino phenyl)methane, diamino diphenyl sulfone,diamino benzophenone, diamino naphthalene, 1,4-bis(4-aminophenoxy)benzene, 1,4-bis(4-amino phenyl)benzene, 9,10-bis(4-aminophenyl)anthracene, 1,3-bis(4-amino phenoxy)benzene,4,4′-bis(4-phenoxy)diphenylsulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis(4-amino phenyl)hexafluoropropane, or2,2-bis[4-(4-amino phenoxy)phenyl]hexafluoropropane, cycloaliphaticdiamines, such as bis(4-amino cyclohexyl)methane, orbis(4-amino-3-methyl cyclohexyl)methane, aliphatic diamines such astetramethylene diamine, hexamethylene diamine, etc., and, further,diaminocyloxanes such as that which is expressed by the chemicalformula:

(where the n represents an integer of from 1 to 10 inclusive).

Also, one, or two or more, kinds of these diamines can be used in a formwherein they are mixed together, too. The concrete examples of thediamine components each of which contains therein a linear alkyl groupthat is used to obtain polyimide used in the present invention includediamino benzene derivatives such as those expressed by the followingchemical formula (2), diamino phenyl derivatives such as those expressedby the following chemical formula (3), diamino turphenyl derivativessuch as those expressed by the following chemical formula (4), diaminodiphenyl ether derivatives such as those expressed by the followingchemical formula (5), diphenyl methane derivatives such as thoseexpressed by the following chemical formula (6), and bis(aminophenoxy)phenyl derivatives such as those expressed by the followingchemical formula (7). The R in each formula is a linear alkyl group,alkyloxy group, alkyloxymethylene group, etc. the carbons number ofwhich is 12 or more.

Also, one, or two or more, kinds of these alkyl diamines can also beused in a form wherein they are mixed together. The concrete examples ofthe monoamine that contains therein a linear alkyl group and that isused to obtain polyimide used in the present invention include aliphaticamines such as those expressed by the following chemical formula (8),cycloaliphatic diamines such as those expressed by the followingchemical formula (9), and aromatic amines such as those expressed by thefollowing chemical formula (10). The R in each formula is a linear alkylgroup, alkyloxy group, alkyloxymethylene group, etc. the carbons numberof which is 12 or more.

Also, one, or two or more, kinds of these alkyl diamines can also beused in a form wherein they are mixed together.NH₂—R  (8)

The concrete examples of the dicarboxylic acid component that containstherein a linear alkyl group and that is used to obtain polyimide usedin the present invention include aliphatic dicarboxylic acids such asthose expressed by the following chemical formula (11), acid anhydridesthereof, and acid halides thereof, cycloaliphatic dicarboxylic acidssuch as those expressed by the following chemical formula (12), acidanhydrides thereof, and acid halides thereof, and aromatic dicarboxylicacids such as those expressed by the following chemical formula (13),acid anhydrides thereof, and acid halides thereof. The R in each formulais a linear alkyl group, alkyloxy group, alkyloxy methylene group, etc.the carbons number of which is 12 or more.

Also, one, or two or more, kinds of these dicarboxylic acid componentscan also be used in a form wherein they are mixed together.

For obtaining the above-described materials, a technique is used ofcausing reaction and polymerization of the tetracarboxylic acidcomponent and the diamine component to thereby produce a polyimide resinprecursor and then performing dehydration, ring closure, and imidizingof that. Generally, as the tetracarboxylic component used at that time,there is used tetracarboxylic acid dianhydride. The ratio of the totalnumber of moles of the tetracarboxylic acid dianhydride to that of thediamine component, preferably, is in a range of from 0.8 to 1.2. As inthe case of an ordinary polycondensation reaction, the nearer to 1 themolar ratio is, the higher the polymerization degree of the polymerproduced becomes.

If the polymerization degree is excessively low, at the time when usingthat material as that of the orientation film, the strength of theresulting polyimide film becomes insufficient with the result that theorientation of the liquid crystal molecule becomes unstable. Also, ifthe polymerization degree is excessively high, in some cases theoperating efficiency at the time of forming a polyimide resin filmbecomes bad. Accordingly, the polymerization degree of the productobtained from the reaction, preferably, is set, when calculated in termsof reduced viscosity of the polyimide precursor solution, to fall withina range of from 0.05 to 3.0 dl/g (having a concentration of 0.5 g/dl inthe solution of N-methylpyrrolidone at 30° C.).

Also, as one of the methods for obtaining the polyimide containingtherein linear alkyl group which is used in the present invention, thereis the one of mixing a diimide compound containing therein a linearalkyl group into the relevant material. For obtaining that diimidecompound, there is a method that is to cause reaction of thedicarboxylic acid component and the diamine component containing thereina linear alkyl group in a molar ratio of 2:1 to thereby make theresulting material a diimide compound precursor and then performdehydration, ring closure, and imidizing of that and/or to causereaction of the monoamine component containing therein a linear alkylgroup and the tetracarboxylic acid dianhydride in a molar ratio of 2:1to thereby make the resulting material a diimide compound precursor andthen perform dehydration, ring closure, and imidizing of that.

Further, as one of the methods for obtaining the polyimide according tothe present invention that contains therein a linear alkyl group, thereis a method of causing introduction of a linear alkyl group into theterminal of the molecular chain of polyimide. In the case of thismethod, there is a method that, when causing reaction and polymerizationof the tetracarboxylic acid component and the diamine component, is tocause reaction of the dicarboxylic acid component containing therein alinear alkyl group and/or a method that, when causing reaction andpolymerization of the tetracarboxylic acid component and the diaminecomponent, is to cause reaction of the monoamine component containingtherein a linear alkyl group. When causing reaction of the dicarboxylicacid component containing therein a linear alkyl group, the ratio a/b ofthe total number (a) of moles of the carboxylic acid residues of thetetracarboxylic acid component and dicarboxylic acid component to thetotal number (b) of moles of the amine residue of the diamine component,preferably, is 2 or less. Also, when causing reaction of the monoaminecomponent containing therein a linear alkyl group, the ratio a′/b′ ofthe total number (a′) of moles of the carboxylic acid residue of thetetracarboxylic acid component to the total number (b′) of moles of theamine residues of the diamine component and monoamine component,preferably, is 2 or more.

In a case where the molar ratio a/b is 2 or more, or the molar ratioa′/b′ is 2 or less, when after the relevant material is formed into apolyimide precursor this precursor is subjected to dehydration, ringclosure, and imidizing, the reaction of the dicarboxylic acid componentor monoamine component becomes insufficient. As a result of this, whenthe resulting material has been used as the liquid crystal orientationprocessor, there is the possibility that it will badly affect theproperty of the liquid crystal. Generally, these tetracarboxylic acidcomponent, diamine component, dicarboxylic acid component, or monoaminecomponent is caused to react in an organic-polar solvent such as asolvent of N-methylpyrrolidone, N,N-dimethyl acetamide, or N,N-dimethylformamide.

The reaction temperature at which these materials are caused to react toobtain a polyimide precursor can be arbitrarily selected from a range offrom −20 to 150°, or preferably from a range of from −5 to 100° C.

Further, by performing heating and dehydration of the polyimideprecursor at a temperature of from 100 to 400° C., or performingchemical imidizing of that by using imidizing catalyst, ordinarily used,such as triethyl amine/acetic anhydride.

b. Polyamide

On the other hand, as the polyamide used in the present invention, therecan be used, for example, the one that is disclosed in an officialgazette of Japanese Patent Application Laid-Open No. 9-230354.

Specifically, there can be taken up as the examples the polyamide thecyclic unit of which can be expressed by the following general formula(14):

(in the formula (14), A represents a bivalent organic group thatconstitutes dicarboxylic acid; and X represents the substituent groupthat is expressed by the following general formula (15):—Y¹—R¹  (15)or the following general formula (16):

and in the formula (15) or (16) above, Y¹ represents an oxygen atom or abivalent group that is expressed by —CH₂O—, —C(═O)O— or —OC(═O)—; R¹represents an alkyl group, or fluorine-containing alkyl group, thecarbons number of which is from 8 to 22 inclusive; Y² represents abivalent organic group that is expressed by —(CH₂)_(n)—, —O(CH₂)_(n)—,—CH₂O(CH₂)_(n)—, —C(═O)O(CH₂)_(n)—, or —OC(═O)(CH₂)_(n)— (n representsan integer of from 2 to 6 inclusive); R² to R⁶ each may be the same ordifferent and each represent an alkyl group that has a carbons number offrom 1 to 6 inclusive; and m represents an integer of 1 or more) and theweight average molecular weight of that is 1000 or more, etc.

As the alkyl group that is represented by the R¹ in the general formula(15), there can be taken up as the examples linear alkyl groups such asoctyl group, nonyl group, undecyl group, decyl group, dodecyl group,tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group,heptadecyl group, octadecyl group, eicosanyl group, and docosanyl groupas well as branching alkyl groups such as 1-ethyl hexyl group, 2-ethylhexyl group, 3-ethyl hexyl group, 1-methyl heptyl group, 2-methyl heptylgroup, 3-methyl heptyl group, 1-methyl octyl group, 2-methyl octylgroup, 2-ethyl octyl group, 1-methyl decyl group, 2-methyl decyl group,3-methyl decyl group, 1-methyl dodecyl group, 1-methyl tetradecyl group,1-methyl hexadecyl group, 1-methyl octadecyl group, 1-methyl eicosanylgroup, and 2-ethyl eicosanyl group.

Also, as the fluorine-containing alkyl group that is represented by theR¹, there can be taken up as the examples the one wherein one or more ofthe hydrogen atoms of the alkyl group have been substituted by fluorineatoms. However, as the alkyl group which is particularly preferable,there can be taken up as the examples perfluoro octyl group, perfluorononyl group, perfluoro undecyl group, perfluoro decyl group, perfluorododecyl group, perfluoro tridecyl group, perfluoro tetradecyl group,perfluoro pentadecyl group, perfluoro hexadecyl group, perfluoroheptadecyl group, perfluoro octadecyl group, perfluoro eicosanyl group,perfluoro docosanyl group, 1H,1H-pentadecafluoro octyl group,1H,1H-heptadecafluoro nonyl group, 1H,1H-nonadecafluoro decyl group,1H,1H-henicosafluoro undecyl group, 1H,1H-tricosafluoro dodecyl group,1H,1H-pentacosafluoro tridecyl group, 1H,1H,2H,2H-tridecafluoro octylgroup, 1H,1H,2H,2H-heptadecafluoro decyl group,1H,1H,2H,2H-henicosafluoro dodecyl group and 1H,1H,2H,2H-pentacosafluorotetradecyl group, 1H,1H,2H,2H-pentacosafluoro tetradecyl group, etc.Incidentally, each of the above-described alkyl group andfluorine-containing alkyl group may be arbitrarily different everycyclic unit.

Also, as the alkyl group that is represented by the R² to R⁶ in thegeneral formula (16), there can be taken up as the examples a linear orbranching lower alkyl group such as a methyl group, ethyl group, propylgroup, isopropyl group, butyl group, isobutyl group, t-butyl group,pentyl group, or hexyl group. However, from the view point of theeasiness with which the relevant materials are synthesized and ofcausing them to exhibit their properties as the liquid crystalorientation film, among the substituent groups that have been enumeratedabove, the methyl group is the most preferable.

c. Polysiloxane

When a thought is given from the viewpoint of performing surfacetreatment with the photocatalyst-containing layer as later described, asthe material used for the orientation layer according to the presentinvention, the material the wettability of which is changed, byexposure, due to the action of the photocatalyst in thephotocatalyst-containing layer it contacts with and which has aprincipal chain unlikely to deteriorate and be decomposed due to theaction of the photocatalyst is preferable. From this point of view,organopolysiloxane can be taken up as the preferable material. Amongall, in the present invention, preferably, the organopolysiloxane is theone that contains therein a fluoroalkyl group.

As that organopolysiloxane, there can be taken up as the example the onethat, through sol/gel reaction or the like, hydrolyzes, and doespolycondensation of, chloro-based material or alkoxysilane or the like,thereby exhibiting a high level of strength.

In that case, preferably, that is the organopolysiloxane that ishydrolytic condensation or co-hydrolytic condensation of one, or two ormore, kinds of a silicon compound that is expressed by the generalformula:Y_(n)SiX(_(4-n))(where Y represents an alkyl group, fluoroalkyl group, vinyl group,amino group, phenyl group or epoxy group; X represents an alkoxyl group,acetyl group, or halogen; and n represents an integer of from 0 to 3inclusive.). Incidentally, here, the groups that each are represented bythe Y preferably each have a carbons number of from 1 to 20 inclusive,and, also, the alkoxy groups that each are represented by the X,preferably, are methoxy group, ethoxy group, propoxy group, and butoxygroup.

Also, there can be preferably used the organopolysiloxane that containstherein, especially as the side chain, the fluoroalkyl group that isillustrated below. In more detail, there can be taken up as the examplesthe hydrolytic condensate and co-hydrolytic condensate of one, or two ormore, kinds of the fluoro alkylsilane that is illustrated below.

-   CF₃(CF₂)₃CH₂CH₂Si(OCH₃)₃;-   CF₃(CF₂)₅CH₂CH₂Si(OCH₃)₃;-   CF₃(CF₂)₇CH₂CH₂Si(OCH₃)₃;-   CF₃(CF₂)₉CH₂CH₂Si(OCH₃)₃;-   (CF₃)₂CF(CF₂)₄CH₂CH₂Si(OCH₃)₃;-   (CF₃)₂CF(CF₂)₆CH₂CH₂Si(OCH₃)₃;-   (CF₃)₂CF(CF₂)₈CH₂CH₂Si(OCH₃)₃;-   CF₃(C₆H₄)C₂H₄Si(OCH₃)₃;-   CF₃(CF₂)₃(C₆H₄)C₂H₄Si(OCH₃)₃;-   CF₃(CF₂)₅(C₆H₄)C₂H₄Si(OCH₃)₃;-   CF₃(CF₂)₇(C₆H₄)C₂H₄Si(OCH₃)₃;-   CF₃(CF₂)₃CH₂CH₂SiCH₃(OCH₃)₂;-   CF₃(CF₂)₅CH₂CH₂SiCH₃(OCH₃)₂;-   CF₃(CF₂)₇CH₂CH₂SiCH₃(OCH₃)₂;-   CF₃(CF₂)₉CH₂CH₂SiCH₃(OCH₃)₂;-   (CF₃)₂CF(CF₂)₄CH₂CH₂SiCH₃(OCH₃)₂;-   (CF₃)₂CF(CF₂)₆CH₂CH₂Si₂CH₃(OCH₃)₂;-   (CF₃)₂CF(CF₂)₈CH₂CH₂Si₂CH₃(OCH₃)₂;-   CF₃(C₆H₄)₃C₂H₄SiCH₃(OCH₃)₂;-   CF₃(CF₂)₃(C₆H₄)C₂H₄SiCH₃(OCH₃)₂;-   CF₃(CF₂)₅(C₆H₄)C₂H₄SiCH₃(OCH₃)₂;-   CF₃(CF₂)₇(C₆H₄)C₂H₄SiCH₃(OCH₃)₂;-   CF₃(CF₂)₃CH₂CH₂Si(OCH₂CH₃)₃;-   CF₃(CF₂)₅CH₂CH₂Si(OCH₂CH₃)₃;-   CF₃(CF₂)₇CH₂CH₂Si(OCH₂CH₃)₃;-   CF₃(CF₂)₉CH₂CH₂Si(OCH₂CH₃)₃; and-   CF₃(CF₂)₇SO₂N(C₂H₅)C₂H₄CH₂Si(OCH₃)₃

By using as the orientation layer the polysiloxane that containstherein, as the side chain, one of the above-enumerated fluoroalkylgroups, the water repellency in the non-exposed portion of thechange-in-wettability layer can be greatly enhanced and, in addition,because of the side chain's being formed, the orientation property canbe greatly enhanced.

(Etceteras)

Regarding the thickness of the orientation film according to the presentinvention, although it is not particularly limited, it preferably fallswithin a range of from 10 Å to 2000 Å. Also, regarding the position atwhich the orientation film of the present invention is disposed, thefilm is disposed at the position at which, in the liquid crystal displaydevice in vertical orientation mode, a relevant orientation film isordinarily disposed, namely in the way of sandwiching the liquid crystallayer. Also, although, ordinarily, the orientation film according to thepresent invention is disposed on either one of the color filter side, oran array substrate side, of the liquid crystal layer, it may be disposedon each side.

B. Method of Manufacturing an Orientation Film

Next, a method of manufacturing the orientation film included in theclaimed scope of the present invention will be explained. The method ofmanufacturing the orientation film according to the present invention ischaracterized by comprising an orientation film-forming process forforming the orientation film on a relevant substrate and apattern-forming process for forming with respect to the surface of theorientation film a pattern including a water-repellent region and ahydrophilic region that is a region where the angle of contact withwater is smaller than that in that water-repellent region.

In the present invention, only by forming the pattern including thewater-repellent region and hydrophilic region on the orientation film inthe above-described way, it is possible to orient the liquid crystalmolecule within the pixel. Accordingly, in a case where the liquidcrystal display device is the one in MVA mode, it becomes possible tomore easily divide the orientation direction of the liquid crystalmolecule within the pixel than do it by the method of, for example,forming a structural member such as the projecting portion.

(Orientation Film Forming Process)

In the orientation film-forming process of the present invention, first,an orientation film-forming process for forming the orientation film onthe relevant substrate is executed.

Here, as the substrate used in the present invention, a transparentmaterial can be used regardless of whether it is the one such as glassthat has no flexibility or the one such as a resinous film that hasflexibility.

Generally, on the substrate, various kinds of functional layersincluding a transparent electrode layer are formed and, on the resultingstructure, there is formed the orientation film.

The method of treatment in that orientation film-forming process isgreatly different depending on the material used therein. Accordingly,there is suitably selected the method of forming the orientation film byconsidering the material that is used, and, then, the orientation filmis formed.

(Pattern-Forming Process)

In the present invention, after executing the above-describedorientation film-forming process, there is executed the pattern-formingprocess for forming with respect to the surface of the orientation filmthe pattern including a water-repellent region and a hydrophilic regionthat is a region where the angle of contact with water is smaller thanthat in the water-repellent region.

In the present invention, the method for forming the above-describedpattern including the water-repellent region and hydrophilic region isnot particularly limited. For instance, as the method, there can betaken up as the example a method of radiating a prescribed active energygrade line such as ultraviolet rays for a long period of time. However,among all, a method that uses a photocatalyst-containing layer issuitably used. The reason for this is that, by using aphotocatalyst-containing layer, it is possible to efficiently form thepattern of hydrophilic region with respect to within the water-repellentregion in a short period of time.

More specifically, it is preferable to use a method of manufacturing anorientation film, wherein the orientation film formed on the substrateis a change-in-wettability layer the wettability on whose surfacechanges due to the action of photocatalyst; and the pattern-formingprocess comprises:

-   -   a photocatalyst-containing layer side substrate-preparing        process for preparing a photocatalyst-containing layer side        substrate that has a photocatalyst-containing layer containing        therein photocatalyst and a base material member; and    -   a photocatalyst-treating process for, after disposing the        photocatalyst-containing layer and the change-in-wettability        layer in the way that the gap therebetween becomes 200 μm or        less, radiating light energy from a prescribed direction onto        the resulting mass to thereby form a pattern, including a        hydrophilic region and a water-repellent region, with respect to        the surface of the change-in-wettability layer.

Hereinafter, an explanation will be given of the method of forming, byusing the photocatalyst, a pattern having different regions ofwettability, with respect to the surface of the orientation film.

1. Change-In-Wettability Layer

In the present invention, the orientation film formed on the substrate,preferably, is a change-in-wettability layer the wettability of whosesurface changes due to the action of the photocatalyst. As the materialof that change-in-wettability layer there can be taken up as theexamples, generally, a compound that has a side chain comprising analkyl group, fluorine-containing alkyl group, or the like, which isdecomposable by photocatalyst. As that compound, more specifically,there can be taken up as the examples polyimide-based compounds,polyamide-based compounds, and polysiloxane-based compounds which wereexplained under the preceding item “A. Orientation film”.

2. Photocatalyst-Containing Layer Side Substrate-Preparing Process

The photocatalyst-containing layer side substrate-preparing processaccording to the present invention is a process for preparing aphotocatalyst-containing layer side substrate having aphotocatalyst-containing layer containing therein photocatalyst and abase material member.

In that way, the photocatalyst-containing layer side substrate that ismanufactured in that process is the one having at least thephotocatalyst-containing layer and a base material member and,ordinarily, is the one wherein there is formed on the base materialmember the photocatalyst-containing layer shaped like a thin film whichhas been formed by a prescribed method. Also, as thatphotocatalyst-containing layer side substrate, there can be used, also,the one having formed thereon a photocatalyst-containing layer sidelight-shielding portion that has been formed into a pattern.

a. Photocatalyst-Containing Layer

The photocatalyst-containing layer used in the present invention is notparticularly limited only if it has a construction wherein thephotocatalyst in the layer causes a change in wettability of thechange-in-wettability layer it contacts with. The layer may be the onethat is constructed using photocatalyst and binder, or the one that hasbeen made using a photocatalyst as simple substance. Also, thewettability of the surface may be hydrophilic or water repellent.

The photocatalyst-containing layer used in the present invention, forexample, as illustrated in FIG. 12, may be the one that has been made aphotocatalyst-containing layer side substrate 3 by aphotocatalyst-containing layer's 2 being formed on the entire surface ofthe base material member 1. However, the layer, for example, asillustrated in FIG. 13, may be the one that is obtained by aphotocatalyst-containing layer's 2 being formed on the base materialmember in the form of a pattern.

By forming the photocatalyst-containing layer as a pattern in that way,as will later be explained in connection with the photocatalysttreatment process, when radiating light energy with thephotocatalyst-containing layer being in contact with thechange-in-wettability, there is no need to perform pattern radiationthat uses a photo-mask or the like. Namely, by performing radiation ofthe light energy with respect to the entire surface, a pattern ofwettability including a hydrophilic region and water-repellent regioncan be formed on the change-in-wettability layer.

Although the method of patterning the photocatalyst-containing layer isnot particularly limited, it can be executed using a photolithographytechnique or the like.

Also, since the wettability of only the portion on thechange-in-wettability layer in actual contact with thephotocatalyst-containing layer changes, the radiation direction ofenergy may be arbitrary only if the direction enables the energy to beradiated onto the portion of contact between thephotocatalyst-containing layer and the change-in-wettability layer.Further, regarding the energy, as well, that is radiated, there is themerit that the energy is not limited to the one that is parallel, suchas parallel light.

The acting mechanism of the photocatalyst, in the above-describedphotocatalyst-containing layer, which is represented by titanium dioxideas later described is not always clear. However, it is considered asbeing the case that the carrier that has been produced by the radiationof light directly reacts with the compounds in the vicinity of that, orcauses the production of active oxygen species in the existence ofoxygen and water to thereby cause a change in the chemical structure ofthe organic material. In the present invention, it is thought that thecarrier acts on the compounds in the change-in-wettability layer thatcontacts with the photocatalyst-containing layer on the same.

As the photocatalyst used in the present invention, there can be takenup as the examples titanium dioxide (TiO₂) that is known asphoto-semiconductor, zinc oxide (ZnO), tin oxide (SnO₂), strontiumtitanic acid (SrTiO₃), tungsten oxide (WO₃), bismus oxide (Bi₂O₃), andiron oxide (Fe₂O₃). By selecting from these compounds, one, or two ormore, kinds of them can be used in a form wherein they are mixed.

In the present invention, especially titanium dioxide is suitably usedbecause the band gap energy thereof is high; it is chemically stable andhas no toxicity; and it is easy to get. As the titanium dioxide, thereare an anatase type one and a rutile type one, either of which can beused in the present invention. However, the anatase type titaniumdioxide is more preferable. The anatase type titanium dioxide has anexcitation wavelength of 380 nm or less.

As that anatase type titanium dioxide, there can be taken up as theexamples anatase type titaniazol of hydrochloric acid peptization type(STS-02 (7 nm in average particle size) produced by Ishihara SangyoKaisha, Ltd.) or ST-K01 manufactured by Ishihara Sangyo Kaisha, Ltd.),anatase type titaniazol of nitric acid peptization type (TA-15 (12 nm inaverage particle size) produced by Nissan Chemical Industries, Ltd.),etc.

The smaller the particle size of the photocatalyst is, the morepreferable the photocatalyst is. This is because in that case thephotocatalytic reaction more effectively occurs. In more detail, it ispreferable to use a photocatalyst the average particle size of which is50 nm or less, more preferable to use a photocatalyst the averageparticle size of which is 20 nm or less.

The photocatalyst-containing layer according to the present inventionmay be the one that is formed using a photocatalyst in an independentform as described above or the one that is formed in a form wherein itis mixed with a binder.

In the case of the photocatalyst-containing layer consisting of only aphotocatalyst, the efficiency with which the wettability on thechange-in-wettability layer changes is enhanced, namely that isadvantageous from the viewpoint of the relevant cost such as shorteningthe treating length of time. On the other hand, in the case of thephotocatalyst-containing layer consisting of a photocatalyst and abinder, there is the merit that forming the photocatalyst-containinglayer is easy.

As the method of forming a photocatalyst-containing layer consisting ofonly a photocatalyst, there can be taken up as the examples the methodseach of which uses a vacuum film-making method such as a sputteringmethod, CVD method, and vacuum deposition method. By forming thephotocatalyst-containing layer through the use of a vacuum film-makingmethod, the photocatalyst-containing layer can be made the one thethickness of which is uniform and which contains therein only aphotocatalyst. As a result of this, it is possible to uniformly changethe wettability on the change-in-wettability layer and, because thelayer consists of only a photocatalyst, compared to the case where abinder is used, to cause a change in the wettability on thechange-in-wettability layer with a high efficiency.

Also, as the method of forming a photocatalyst-containing layerconsisting of only a photocatalyst, as far as the case where thephotocatalyst is, for example, titanium dioxide is concerned, there canbe taken up as the examples a method that forms amorphous titania on thebase material member and then phase-changes it into crystalline titaniaby baking, etc. The amorphous titania used here can be obtained byperforming hydrolysis and dehydration condensation of inorganic salt oftitanium such as titanium tetrachloride, titanium sulfate, etc., or byperforming hydrolysis and dehydration condensation in the presence ofoxygen an organic titanium compound such as tetra-ethoxy titanium,tetra-isopropoxy titanium, tetra-n-proxy titanium, tetra-butoxytitanium, and tetra-methoxy titanium. Subsequently, the amorphoustitania can be denatured into anatase type titania by baking done at atemperature of 400° C. to 500° C. and then into rutile type titania bybaking done at 600° C. to 700° C.

Also, in the case of using a binder, using the one having a high bondenergy, the principal skeleton of that is not decomposed byphoto-excitation of the above-described photocatalyst, is preferable,and, there can be taken up as the examples a polysiloxane-based materialexplained as the materials under the preceding item “Orientation film”,etc.

In a case where using polysiloxane as the binder in that way, thephotocatalyst-containing layer can be formed by dispersing into thephotocatalyst and polysiloxane binder into a solvent together withadditives if necessary and thereby preparing a coating solution and thencoating it onto the base material member. As the solvent used, analcoholic organic solvent such as ethanol, isopropanol, etc. ispreferable. The coating can be performed with a known coating methodsuch as spin coating, spray coating, dip coating, roll coating, beadcoating, etc. In a case where the relevant material contains therein anultraviolet ray-hardenable component as the binder, radiatingultraviolet rays is performed to thereby perform hardening treatment ofthat to enable forming a photocatalyst-containing layer.

Also, the invention can use an amorphous silica precursor as the binder.This amorphous silica precursor is expressed by the general formula SiX₄and, in this formula, X preferably is a silicon compound such ashalogen, methoxy group, ethoxy group, or acetyl group, silanol that is ahydrolytic material thereof, or polysiloxane the average molecularweight of which is 3000 or less.

More specifically, the amorphous silica precursor includes as theexamples tetraethoxy silane, tetraisopropoxy silane, tetra-n-propoxysilane, tetrabutoxy silane, and tetramethoxy silane. Also, in that case,the amorphous silica precursor and the photocatalyst particles areuniformly dispersed in a non-aqueous solvent; the resulting material ishydrolyzed using the water content in the air, thereby silanol is formedon the base material member; then the resulting material is subjected todehydration and condensation/polymerization at normal temperature; and aphotocatalyst-containing layer can thereby be formed. If dehydration andcondensation/polymerization of silanol are performed at 100° or more,the polymerization degree of silanol can be increased to therebyincrease the strength on the surface of the film layer. Also, thosebonding agents can be used, individually independently, or in a formwherein two or more kinds of them are mixed together.

The content of the photocatalyst in the photocatalyst-containing layerin the case of using a binder can be set to a range of from 50 to 60% byweight, or preferably to a range of from 20 to 40% by weight. Also, thethickness of the photocatalyst-containing layer preferably is in a rangeof from 0.05 to 10 μm.

Also, the photocatalyst-containing layer can be made to contain thereina surface activator other than the above-described photocatalyst andbinder. Specifically, there can be taken up as the examples ahydrocarbon-based nonionic surface activator such as respective seriesof NIKKOL, BL, BC, BO, and BB that are produced by Nikko Chemicals Co.Ltd. or a fluorine-based, or silicone-based, nonionic surface activatorsuch as ZONYL, FSSN, and FSO that are produced by Du Pont KabushikiKaisha, Surflon S-141, 145 that are produced by Asahi Glass CompanyMegafuck F-141, 144 that are produced by Dainippon Ink and Chemicals,Incorporated, Phthagent F-200, F251 that are produced by Neos,UNIDYNEDS-401, 402 that are produced by DAIKIN INDUSTRIES, Ltd., andFluorad FC-170, 176 that are produced by 3M. Also, it is also possibleto use a cationic surface activator, anionic surface activator, orampholytic surface activator.

Other than the above-described surface activators, there can also becontained in the photocatalyst-containing layer oligomer such aspolyvinyl alcohol, unsaturated polyester, acrylic resin, polyethylene,diallyl phthalate, ethylene propylene diene monomer, epoxy resin, phenolresin, polyurethane, melamine resin, polycarbonate, polyvinyl chloride,polyamide, polyimide, styrene butadiene rubber, chloropulene rubber,polypropylene, polybutylene, polystyrene, polyvinyl acetate, polyester,polybutadiene, polybenzimidazole, polyacrylnitryl, epichlorohydrin,polysulfide, or polyisoprene, or polymer, or etc.

b. Base Material Member

In the present invention, as illustrated in FIG. 12, thephotocatalyst-containing layer side substrate 3 is the one that has atleast a base material member 1 and a photocatalyst-containing layer 2formed on the base material member 1.

At this time, the material constituting the base material member that isused for the substrate is suitably selected depending on the radiationdirection of energy in the photocatalyst treatment process that will bedescribed later. Namely, in a case where, in the photocatalyst treatmentprocess as later described, performing exposure from the rear surface ofthe photocatalyst-containing layer side substrate, the material needs tobe transparent material. However, in a case where exposure is performedfrom the change-in-wettability layer side, the material is notparticularly limited to transparent material.

Also, the base material member used in the present invention may be theone that has flexibility such as a resinous film or the one that has noflexibility such as a glass substrate. The material of the base materialmember, also, is suitably selected depending on the energy radiationmethod in the photocatalyst treatment process as later described.

Like that, the base material member used in the photocatalyst-containinglayer side substrate in the present invention is not particularlylimited in terms of material. However, since thephotocatalyst-containing layer side substrate is repeatedly used, amaterial that has a prescribed level of physical strength and thesurface of that has excellent adhesion to the photocatalyst-containinglayer is preferable.

In more detail, there can be taken up as the examples glass, ceramic,metal, plastic, etc.

Incidentally, to enhance the adhesion between the surface of the basematerial member and the photocatalyst-containing layer, a primer layermay be formed on the base material member. As that primer layer, therecan be taken up as the examples silane-based coupling agent,titanium-based coupling agent, etc.

c. Photocatalyst-Containing Layer Side Light-Shielding Portion

As the photocatalyst-containing layer side substrate used in the presentinvention, there may be used the one having formed with respect theretoa photocatalyst-containing layer side light-shielding portion formedinto the configuration of a pattern. By using thephotocatalyst-containing layer side substrate that has thephotocatalyst-containing layer side light-shielding portion like that,when performing exposure, there is no need either to use a photo-mask orto perform depiction radiation that uses a laser light. Since,accordingly, there is no need to perform positional alignment of thephoto-mask with the photocatalyst-containing layer side substrate, therelevant process of exposure can be made simple, nor is there any needto use an expensive device necessary for performing depiction radiation.Therefore, there is the merit that using the substrate becomesadvantageous in terms of the relevant cost.

As that photocatalyst-containing layer side substrate that has thephotocatalyst-containing layer side light-shielding portion, thefollowing two embodiments can be adopted depending on the formationposition where the photocatalyst-containing layer side light-shieldingportion is formed.

One is the embodiments wherein, as illustrated in, for example, FIG. 14,the photocatalyst-containing layer side light-shielding portion 13 isformed on the base material member 1; and on this light-shieldingportion 13 there is formed the photocatalyst-containing layer 2 to makethe resulting mass the photocatalyst-containing layer side substrate 3.The other is a mode of embodiment wherein, as illustrated in, forexample, FIG. 15, the photocatalyst-containing layer 2 is formed on thebase material member 1; and on the member there is formed thephotocatalyst-containing layer side light-shielding portion 13 to makethe resulting mass the photocatalyst-containing layer side substrate 3.

In either embodiment, compared with the case where using a photo-mask,the photocatalyst-containing layer side light-shielding portion comes tobe disposed in the vicinity of the portion of contact between thephotocatalyst-containing layer and the change-in-wettability layer. Thiscan lessen the effect of the scattering of the energy within, forexample, the base material member, which enables performing patternradiation of energy very accurately.

Further, in the embodiment that forms the photocatalyst-containing layerside light-shielding portion on the photocatalyst-containing layer, whendisposing the photocatalyst-containing layer and thechange-in-wettability layer with a prescribed gap interveningtherebetween, the thickness of the photocatalyst-containing layer sidelight-shielding portion can be made to coincide with the dimension ofthat prescribed gap beforehand if it is preferable that those both bedisposed with a prescribed gap intervening therebetween as laterdescribed. By doing so, the merit comes up that thephotocatalyst-containing layer side light-shielding portion can be usedas the spacer for making that prescribed gap a fixed one.

Namely, by, when disposing the photocatalyst-containing layer and thechange-in-wettability layer with a prescribed gap in between, disposingthe photocatalyst-containing layer side light-shielding portion and thechange-in-wettability layer in a state of these layers' being made toadhere to each other, the prescribed gap becomes able to be madeaccurate in terms of the dimension. Further, by radiating energy, inthat state, from the photocatalyst-containing layer side substrate, thepattern of wettability becomes able to be formed on thechange-in-wettability layer with a high accuracy.

The method of forming such photocatalyst-containing layer sidelight-shielding portion is not particularly limited but is suitablyselected and used according to the property of the formation surfacewhere formation is made of the photocatalyst-containing layer sidelight-shielding portion, the shielding property with respect to energyneeded, etc.

For instance, a method may be adopted of forming a metallic thin filmsuch as chrome, the thickness of which is to an extent of 1000 to 2000Å, with the use of a sputtering method, vacuum deposition method, etc.and then patterning the thin film. This patterning method may be anordinary patterning method such as sputtering.

The above-described forming method may be the one wherein a layer thathas been prepared by causing containing into a resinous binder oflight-shielding particles such as carbon fine particles, metal oxide,inorganic pigment, organic pigment, etc. is formed into a pattern. Asthe resinous binder used, there can be used a material obtained bymixing together one, or two or more, kinds of resins such as polyimideresin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol,gelatin, casein, cellulose, etc., photosensitive resin, or O/W emulsiontype resinous composition such as the one prepared by converting areactive silicone into an emulsion. The thickness of the resin-madelight-shielding portion can be set to a value falling within a range offrom 0.5 to 10 μm. As the method of patterning the resin-madelight-shielding portion, there can be used a method such asphotolithography, printing, etc. that is generally used.

Incidentally, although in the above-described explanation it has been,as the formation position where formation is made of thephotocatalyst-containing layer side light-shielding portion, given oftwo cases one of which is the case where that position is locatedbetween the base material member and the photocatalyst-containing layerand the other of which is the case where that position is located on thesurface of the photocatalyst-containing layer, other than this it isalso possible to adopt an embodiment wherein thephotocatalyst-containing layer side light-shielding portion is formed onthe surface of the base material member that is on a side where nophotocatalyst-containing layer is formed. As the embodiment, a methodwherein, for example, a photo-mask is made to adhere to the surface toan extent that permits it to be removably attached thereto, etc. isthought available and, in this case, the method can be used for examplewhen causing a change of the wettability pattern in a small lot.

3. Photocatalyst Treatment Process

In the present invention, next, the photocatalyst treatment process isexecuted wherein the photocatalyst-containing layer and thechange-in-wettability layer are disposed in the way of their beingcontacted with each other and thereafter energy is radiated onto theresulting mass from a prescribed direction to thereby form a wettabilitypattern including a hydrophilic region and a water-repellent region onthe surface of the change-in-wettability layer.

a. Disposing Photocatalyst-Containing Layer and Change-in-WettabilityLayer

In this process, first, when performing radiation of energy, thephotocatalyst-containing layer and the change-in-wettability layer aredisposed with a gap of 200 μm or less intervening in between.

In the present invention, that gap may not be provided and thephotocatalyst-containing layer and the change-in-property layer may bemade to adhere to each other. However, considering the pattern accuracyand the aspect of increasing the efficiency of changing the property ofthe change-in-property layer, the gap preferably is set to fall within arange of 100 μm or less, especially a range of from 0.2 μm to 10 μm.

By disposing the photocatalyst-containing layer and the surface of thechange-in-property layer with a prescribed gap in between in theabove-described way, the oxygen and the water as well as the activeoxygen species produced due to the photo-catalytic action become easierto detach or attach. Namely, in a case where making the gap between thephotocatalyst-containing layer and the change-in-property layer narrowerthan a value falling within the above-described range, the active oxygenspecies comes to have more difficulty of detaching or attaching. As aresult of this, there is the possibility that the speed at which theproperty is changed will be slowed down. From this point of view, thecase is unpreferable. In a case where the disposition is made with thegap in between the dimension of which is greater than a value fallingwithin that range, the active oxygen species produced becomes moredifficult to reach the change-in-property layer. In this case as well,there is the possibility that the speed at which the property is changedwill be slowed down. From this point of view, the case also isunpreferable.

In the present invention, the disposition condition in which theabove-described gap intervenes in between needs only to be maintained atleast during the exposure.

As the method of disposing the photocatalyst-containing layer andchange-in-wettability layer with the gap being uniformly provided whichis very narrow as described above, there can be taken up as the examplea method wherein a spacer is used. Further, by using the spacer likethat, it is possible to form a uniform gap. In addition, since theportion that the spacer contacts with acts to prevent the photocatalyticaction from extending to the surface of the change-in-wettability layer,a prescribed pattern of wettability becomes able to be formed on thechange-in-wettability layer by forming this spacer so that it may have apattern similar to the wettability pattern described above.

In the present invention, although that spacer may be formed as aseparate, single member, for simplifying the process it is preferablethat, as has been explained under the preceding item“Photocatalyst-containing layer side substrate-preparing process”, thespace be formed on the surface of the photocatalyst-containing layer ofthe photocatalyst-containing layer side substrate. Incidentally, in theexplanation made in the photocatalyst-containing layer sidesubstrate-preparing process, the spacer was explained as thephotocatalyst-containing layer side light-shielding portion. However, inthe present invention, because the spacer may be the one that needs onlyto have a function to protect the surface of the change-in-wettabilitylayer so as to prevent the photocatalytic action from extending to it,the spacer may be the one that is formed using a material having nofunction to shield energy that is to be radiated.

b. Radiating Energy Onto the Gap Portion

Next, in the state where the both layers are disposed with theabove-described gap in between is maintained as is, radiation of energyis performed with respect to the gap portion. Incidentally, the wording“radiation of energy (exposure)” referred to in the present invention isa concept that includes any radiation of energy that enables a change inwettability of the surface of the change-in-wettability layer by thephotocatalyst-containing layer, and that is not limited to energy of avisible light.

Ordinarily, the wavelength of light used for the exposure is set from arange of 400 nm or less, preferably from a range of 380 nm or less. Thisis because the preferable photocatalyst used in thephotocatalyst-containing layer is titanium dioxide as described aboveand, if this titanium is used, as the energy that activates thephotocatalytic action a light having the wavelength is preferable.

As the light source that can be used for the exposure, there can betaken up as the examples a mercury lamp, metal halide lamp, Xenon lamp,excimer lamp, and other various kinds of light sources.

In addition to the methods that perform pattern radiation via aphoto-mask using above-mentioned light sources, it is also possible touse the method that performs depiction radiation as a pattern by usinglaser light such as an excimer, YAG etc.

Also, the radiating amount of energy that is used when performingexposure is defined as being the one that is needed for the surface ofthe change-in-wettability layer to have its wettability changed due tothe action of the photocatalyst in the photocatalyst-containing layer.

At this time, by performing exposure while heating thephotocatalyst-containing layer, the sensitivity becomes able to beincreased. That, therefore, is preferable because efficiently changingthe wettability can be performed. Specifically, heating within a rangeof from 30° C. to 80° C. is preferable.

The exposure direction in the present invention is determined dependingon the method of forming the wettability such as whether or not thephotocatalyst-containing layer side light-shielding portion is formed,or depending on whether the photocatalyst-containing layer sidesubstrate is transparent.

Namely, in a case where the photocatalyst-containing layer sidelight-shielding portion is formed, there is the need for exposure to bedone from the photocatalyst-containing layer side substrate side and, inaddition, in that case, there is the need for thephotocatalyst-containing layer side substrate to be transparent withrespect to the energy that is radiated. Incidentally, in this case, ifthe photocatalyst-containing layer side light-shielding portion isformed on the photocatalyst-containing layer and, in addition, thelight-shielding portion is used in the way of its having a function asthe spacer as stated before, the exposure direction may be from thephotocatalyst-containing layer substrate side or from thefor-pattern-formation substrate side.

Also, the exposure direction when the photocatalyst-containing layer isformed as a pattern may be any given one only if energy is radiated ontothe gap portion between the photocatalyst-containing layer and thechange-in-wettability layer as described above.

Similarly, in a case, as well, where using the above-described spacer,the exposure direction may be any given one only if energy is radiatedonto the portion of gap.

If using a photo-mask, energy is radiated from the side where it isdisposed.

c. Removing Photocatalyst-Containing Layer Side Substrate

When the above-described radiation of energy finishes being performed,the photocatalyst-containing layer side substrate is taken away from theposition of its being opposed to the change-in-wettability layer,whereby a pattern of wettability including a hydrophilic region and awater-repellent region is formed on the change-in-wettability layer.

4. Etceteras

Regarding the other respects in the present invention, such as, forexample, the matter on the water-repellent region and the hydrophilicregion, they are the same as those that were explained under thepreceding item “A. Orientation film” and therefore an explanationrelevant thereto is omitted here.

C. Substrate with Orientation Film

Next, an orientation film-equipped substrate according to the presentinvention will be explained. The orientation film-equipped substrateaccording to the present invention is characterized by having asubstrate and an orientation film that is formed on the substrate andthat has a pattern including a water-repellent region and a hydrophilicregion that is a region where the angle of contact with water is smallerthan that in the water-repellent region. By having the orientation filmwherein the hydrophilic region is formed within the water-repellentregion as a pattern, in a case of having used the resulting substratein, for example, the liquid crystal display device in verticalorientation mode, it becomes possible to perform orientation divisionwithin the relevant pixel of the liquid crystal molecule that hasvertically been oriented. Namely, that becomes possible throughutilizing the nature of the liquid crystal molecule that thisliquid-crystalline molecule that within the water-repellent region isvertically oriented gets inclined when within the hydrophilic region.

FIG. 16 illustrates an example of the above-described orientationfilm-equipped substrate according to the present invention, i.e.illustrates a state where the orientation film 5 is formed on thesubstrate 4 via a transparent electrode layer 9.

The orientation film used in the orientation film-equipped substrateaccording to the present invention is the same as that which has beenexplained under the preceding item “A. Orientation film”. Therefore, anexplanation relevant thereto is omitted here.

Also, the substrate used in the present invention ordinarily is atransparent substrate and may be the one such as glass that has noflexibility or the one such as transparent resin that has flexibility.

As illustrated in, for example, FIG. 17, in the present invention,ordinarily, a liquid crystal layer 6 is disposed on the side of thesurface of the orientation film.

Incidentally, by utilizing the orientation film of the presentinvention, it is also possible to form a semi-transparent reflectivefilm using a technique of orienting and hardening a hardenablecholesteric liquid crystal (e.g. a mixture of hardenable nematic liquidcrystal and hardenable kairal agent) Also, using a hardenable nematicliquid crystal, hardenable short-pitch cholesteric liquid crystal, orhardenable discotic liquid crystal, as above, it is possible to orientand harden it with the orientation film of the present invention to forma difference-in-phase layer having an index of double refraction and useit as an optical compensation sheet.

For the liquid-crystalline molecule, which is a negative typeliquid-crystalline material having a negative dielectric constantanisotropy, used in the above-described liquid crystal layer, thematerial is not particularly limited if at normal temperature it is theone having a nematic phase. Specifically, there can be taken up as theexamples MLC-6608, MLC-2037, MLC-2038, and MLC-2039 (each of that is atrade name) of Merck & Co., Inc.

The orientation film-equipped substrate of the present invention may bethe one wherein other layers are formed between the substrate and theorientation film. Or it may be the one wherein, as illustrated in, forexample, FIG. 18, a colored layer 7 and a light-shielding portion (blackmatrix) 8 formed at the boundary portion thereof are provided on asubstrate 4; on the color layer 7 and the light-shielding portion 8there is provided the transparent electrode layer 9; and on the layer 9there is formed the orientation film 5, etc.

The above-described colored layer and light-shielding portion used inthe present invention is not particularly limited if they are the onesthat are ordinarily used in the color filter. For the colored layer, aphotosensitive resin that contains therein a red, blue, or green pigmentthat is used in an ordinary technique of pigment dispersion, etc. issuitably used. For the light-shielding portion, metal such as chrome, aresin having dispersed therein particles having light-shielding propertysuch as carbon black, etc. are suitably used.

Also, the transparent electrode layer is not particularly limited, but,generally, ITO is suitably used.

D. Liquid Crystal Display Device

Finally, the liquid crystal display device of the present invention willbe explained. The liquid crystal display device of the present inventionis characterized by comprising:

-   -   a color filter side substrate that has a first substrate, a        colored layer that is formed on the first substrate, a        transparent electrode layer formed on the colored layer, and an        orientation film that is formed on the transparent electrode        layer and that has on its surface on a side where a liquid        crystal layer is contacted therewith a pattern including a        water-repellent region and a hydrophilic region that is a region        where the angle of contact with water is smaller than that in        the water-repellent region, and    -   an opposing substrate that has a second substrate, a transparent        electrode layer formed on the second substrate, and an        orientation film that is formed on the surface of the        transparent electrode layer and that has on its surface on a        side where a liquid crystal layer is contacted therewith a        pattern including a water-repellent region and a hydrophilic        region that is a region where the angle of contact with water is        smaller than that in the water-repellent region,    -   whereby the orientation film of the color filter side substrate        and the orientation film of the opposing substrate are disposed        in the way they oppose each other; and    -   liquid crystal is sealed into between the two orientation films.

The liquid crystal display device mentioned like that is the one thathas an orientation film wherein the hydrophilic region is formed withinthe water-repellent region as a pattern. Therefore, in, for example, theliquid crystal display device in vertical orientation mode, theorientation division within the pixel of the liquid crystal moleculethat has vertically been oriented becomes able to be made by the natureof the liquid crystal molecule that this molecule that within thewater-repellent region is vertically oriented gets inclined within thehydrophilic region.

An example of the above-described liquid crystal device is illustratedin FIG. 19. First, the color filter side substrate having formed thereina color filter has the first substrate 21 on which there is formed thecolored layer 7 that ordinarily has a pattern of red, green, and blue.Further, on that surface there is formed the transparent electrode layer9 and, further, on the surface of the resulting structure, there isformed the orientation film 5 as stated above.

On the opposing substrate that opposes the color filter side substratehas the second substrate 22, on which the transparent electrode 9 isformed, on which the above-described orientation film 5 is formed.

Incidentally, either the transparent electrode layer of the color filterside substrate or the transparent electrode layer of the opposingsubstrate side may be the one that has been formed in the mode of activematrix.

The orientation film 5 of the color filter side substrate and theorientation film 5 of the opposing substrate side are disposed in theway of their opposing each other. Further, into the gap between thesetwo films there are sealed the liquid crystal molecules. As a result ofthis, a liquid crystal layer 6 is formed. The structure that has thusbeen obtained is made the liquid crystal device of the presentinvention.

The above-described orientation film used in the liquid crystal displaydevice according to the present invention is the same as that which hasbeen explained in connection with the preceding item “A. Orientationfilm”, so an explanation relevant thereto is omitted. Also, the otherfirst and second substrates are the same as that which has beenexplained in connection with the preceding item “C. Substrate withorientation film” and, further, regarding the colored layer andtransparent electrode layer as well and, further, regarding the liquidcrystal layer as well, each of them is the same as that which has beenexplained under the preceding item “C. Substrate with orientation film”,so an explanation relevant thereto is omitted.

It is to be noted that the present invention is not limited to theabove-described embodiment. The above-described embodiment is onlyillustrative. The changes or modifications that have substantially thesame constructions as those which are made using the technical ideasdescribed in the claimed scope of the present invention and exhibit thesame functions and effects are included in the technical scope of thepresent invention whatever kinds they may be of.

EXAMPLES

Hereinafter, the present invention will concretely be explained usingExamples.

Example 1

First, an orientation film was coated (applied) onto each of upper andlower substrates and, as the orientation film of the lower sidesubstrate, the one that has formed thereon a wettability pattern havinga water-repellent region and hydrophilic region was used.

The orientation film was prepared as follows. On a quartz glasssubstrate having formed thereon a pattern of light-shielding layer madeof chrome, there was coated a for-use-as-photocatalyst titanium oxidecoating material ST-K03 produced by Ishihara Sangyo Kaisha, Ltd. Theresulting mass was dried at 150° C. for 15 minutes to complete aphoto-mask with photocatalyst-containing layer (a pattern-equippedsubstrate).

Next, 3 grams of an 0.1N aqueous solution of hydrochloric acid was addedto a mixture of 5 grams of fluoroalkyl silane and 2 grams of tetraethoxysilane and the resulting mass was stirred at room temperature for 1 hourto prepare a solution. The solution was coated onto the substrate andthe resulting substrate was dried at 150° C. for 10 minutes to form achange-in-wettability layer.

Onto the resulting substrate, there was adhered the above-describedphoto-mask. Then, using an ultrahigh mercury lamp, ultraviolet rays wereradiated onto the resulting mass from the photo-mask side, at anilluminance of 20 mW/cm² (365 nm), for 180 seconds, to thereby form apattern of wettability on the surface of the change-in-wettabilitylayer. At this time, the angle of contact with water at the non-exposedportion was 108° while the angle of contact with water at the exposedportion was 7°. The gap between the substrates was 5 μm. Incidentally,this gap was controlled using a spacer that was disposed in the liquidcrystal layer and that gap was almost uniform within the display panelsurface. As the spacer, there was used an SP series produced by FineChemicals Division, Sekisui Chemical Co., Ltd.

Between the substrates, a thermo-hardenable sealing material was coatedon each of their outer-peripheral surfaces, and then they were bondedtogether. For controlling the gap between the substrates, the cell washeated while being pressed, thereby the seals were cured. As the sealingmaterial, there was used XN-54 produced by Mitsui Chemicals Inc. Intothat cell, a liquid crystal material was filled with the use of a vacuuminjection technique. As the liquid crystal material there was used anMLC 6608 (trade name) material produced by Merck & Co., Inc. This liquidcrystal has negative dielectric anisotropic property and has the naturethat, when an electric field is applied, its molecular long axis getsvertically oriented with respect to the direction in which the electricfield is formed.

In FIG. 7 illustration is made of a state of no electric field's beingapplied, a state of a voltage's that is intermediate being applied, anda state of an electric field's being applied, of the liquid crystaldisplay device obtained as above.

FIG. 20A illustrates an oriented state when no electric field isapplied. In this case, since the orientation film of each of theupper/lower substrates exhibits substantially hydrophobic property, theliquid crystal molecule is substantially vertically oriented. In theorientation film hydrophilic region of the lower substrate and in thevicinity thereof, the liquid crystal molecule is oriented in a state ofits being somewhat inclined but this inclination is almost near to astate of verticalness. Therefore, even when the incident light passesthrough the liquid crystal layer, the plane of polarization does notchange and the light is absorbed into a polarizing plate of the outgoingside. Resultantly, a display in black was obtained.

FIG. 20B is a view illustrating a state where there has been applied avoltage that causes the liquid crystal to come to a state of itsinclined orientation's being intermediate between the horizontalorientation and the vertical orientation. That state results in adisplay in half tone. In the hydrophilic region of the orientation film,with the molecule that is previously inclined being the starting point,the directions in which the molecules are inclined are determined, andthereby their orientation is divided. Since the regions wherein theinclinations of the liquid crystal molecules differ are formed aplurality of pieces within the relevant pixel, the difference in thepassing amount of light that results from the difference in the viewingangle was complementarily averaged, with the result that the dependencyon the viewing angle became better.

FIG. 20C illustrates a state where a voltage is sufficiently applied andthe liquid crystal is almost horizontally oriented. In this case, adisplay in white was made.

Example 2 Polyimide-Made Orientation Film

As the vertical orientation film material, there were used JALS-688,JALS-204, JALS-2021, and JALS-2022 produced by JSR. and SE-751L andSE-1213 produced by Nissan Chemical Industries, Ltd. Using aspin-coating technique, onto the ITO-equipped glass substrate there wascoated each of the above-described PI's, and the resulting mass wasbaked at 220° C. for one hour.

Spin coating was performed for 5 seconds at 600 rpm and subsequently for15 seconds at 2400 rpm. The thickness of the orientation film wasmeasured using a direct-needle type film thickness meter, the result ofwhich was 600 Å. Although that polyimide film was a hydrophobic film, byperforming ultraviolet-ray exposure through the intermediary of theexposure mask having the photocatalyst-containing layer coated on itsuppermost surface, a pattern of hydrophilic region could be formedwithin the hydrophobic region.

In this Example, a mass wherein the photocatalyst-containing layer isformed on the exposure mask that has a light-shielding region in stripeseach 50 μm in width and a light-passing region in stripes each 25 μm inwidth was used as the orientation film substrate.

As a result, a hydrophobic region 50 μm in width and a hydrophilicregion 25 μm in width were formed on the substrate. The angle of contactwith water that is on the surface of the hydrophobic region was 96°,namely a sufficiently high level of water repellency was exhibited.Also, exposure was performed via the substrate having thephotocatalyst-containing layer with no light-shielding pattern thereonand, in this case, in the portions where the hydrophilic region wasmade, since the angle of contact with water changes within a range offrom approximately 10° to approximately 30°, it was observed that thelevel of wettability was sufficiently changed and the relevant portionswere sufficiently made hydrophilic.

The above-described substrate and another substrate having disposedtherein the same vertical-orientation polyimide were positionallyaligned with each other and bonded together. At this time, in order tomake the gap between the substrates almost 5 μm, an SP series materialproduced by Fine Chemicals Division, Sekisui Chemical Co., Ltd. wasspread over the other substrate. Regarding the spread density, it wascontrolled so as to become approximately 10 to 200 pieces/mm2. Thespreading method was executed using a dry-spreading technique.

In order to ensure the attainment of the adhesion between the upper andthe lower substrate as well as the closed space into which liquidcrystal is to be filled, sealing material was coated onto theouter-peripheral part of each of the substrates to a width ofsubstantially 1 mm. Then, the resulting structures were subjected topressing and then each sealant was thermo-hardened.

A negative type liquid crystal material of MLC-6608 that is produced bythe Merck & Co., Inc. was injected into the resulting structure toprepare a liquid crystal cell. When observing with a polarizingmicroscope, the initial orientation was obtained as the verticalorientation. Further, when applying a voltage to that liquid crystalcell, there was observed a state where the liquid crystal director waslaid substantially parallel with the boundary between the hydrophilicregion and the hydrophobic region. When a sufficiently high level ofvoltage was applied, the horizontal orientation wherein the director waslaid alongside that boundary was obtained.

Example 3 IPS Mode

The IPS mode is a horizontally oriented liquid crystal mode, andhorizontal-orientation processing is performed with respect to thesubstrate. In this Example, as the change-in-wettability layer, therewas used fluorine-based silicone, and, by designing the region occupiedby the hydrophilic property to an area that is equal to or greater thanthat corresponding to the region occupied by the hydrophobic property,the horizontal orientation was obtained.

Using a spin coating technique, a fluorine-based silicone that had beenused in Example 1 was coated onto the ITO-equipped glass substrate toform a relevant film. Although this fluorine-based silicone film is ahydrophobic film, by performing ultraviolet-ray exposure with respect toit via the exposure mask having the photocatalyst-containing layercoated on its uppermost surface, a pattern of hydrophilic region andhydrophobic region could be disposed on the substrate. This pattern isillustrated in FIG. 6. In this Example, the photocatalyst layer isformed on the exposure mask having a light-shielding region in stripeseach 20 μm in width and a light-passing region in stripes each 20 μm inwidth.

Concretely, as illustrated in FIG. 6, a hydrophobic region 20 μm inwidth and a hydrophilic region 20 μm in width were formed on thesubstrate.

The fluorine-based silicone film has a sufficient level of waterrepellency when the angle of contact with water thereof is around 110degrees. Also, when exposure is performed via the substrate that has thephotocatalyst-containing layer with no light-shielding pattern to form ahydrophilic region, the angle of contact with water changes within arange of from approximately 0 to approximately 10°, for which reason, itwas observed that the wettability sufficiently changed and the film wasmade sufficiently hydrophilic.

The above-described substrate was positionally aligned with anothersubstrate having disposed therein the same pattern of hydrophilicity andwas bonded or adhered thereto. At this time, for making the gap betweenthe substrates approximately 3 to 4 μm, SP series produced by FineChemicals Division, Sekisui Chemical Co., Ltd. was spread with respectto the other substrate.

Regarding the density of spreading, it was controlled so that it may be10 to 200 pieces/mm² or so. For ensuring the adhesion between the upperand the lower substrate as well as the closed space into which liquidcrystal is to be filled, sealing material was coated onto theouter-peripheral part of each substrate to a width of approximately 1mm. After the sealant was pressed, it was thermo-hardened.

A liquid material of MLC-2042 for IPS produced by Merck & Co., Inc. wasinjected to prepare a liquid crystal cell. When the resulting structurewas observed using a polarizing microscope, a state where the directorgot substantially parallel with the boundary between the hydrophilicregion and the hydrophobic region was observed.

Further, the state was observed where the liquid crystal director withinthe liquid crystal cell was coming, according to the intensity of theelectric field applied, near to the electric lines of force direction ofthe electric field applied.

Example 4 TN Mode

The surface of the substrate in TN mode is a horizontally orientedliquid crystal mode, and horizontal orientation processing is executedwith respect to the substrate. In this Example, for thechange-in-wettability layer, there was used the fluorine-based siliconethat had been used in Example 1.

Designing was done in the way that the region occupied by hydrophilicitywas equal to or greater than the region occupied by hydrophobicity, and,horizontal orientation processing was executed with respect to theresulting mass. Thereby, a cell illustrated in FIG. 9, which wasconfigured in the way that the orientation direction of the uppersubstrate and that of the lower substrate intersected each other at aright angle, was prepared.

Using a spin coating technique, a fluorine-based silicone that had beenused in Example 1 was coated onto the ITO-equipped glass substrate toform a relevant film. This fluorine-based silicone film was ahydrophobic film. On the other hand, by performing ultraviolet-rayexposure with respect to it via the exposure mask having thephotocatalyst-containing layer coated on its uppermost surface, ahydrophilic region and hydrophobic region could be disposed on thesubstrate. In this Example, the photocatalyst layer was formed on theexposure mask having a light-shielding region in stripes each 20 μm inwidth and a light-passing region in stripes each 20 μm in width.

Using the resulting mass, a hydrophobic region 20 μm in width and ahydrophilic region 20 μm in width were formed on the substrate. Thefluorine-based silicone film has a sufficient level of water repellencywhen the angle of contact with water thereof is around 110 degrees.Also, when exposure is performed via the substrate that has thephotocatalyst-containing layer with no light-shielding pattern, theangle of contact with water changes within a range of from approximately0 to approximately 10°, for which reason, it was observed that thewettability sufficiently changed and the film was made sufficientlyhydrophilic.

The above-described substrate was positionally aligned with anothersubstrate having disposed therein the same pattern of hydrophilicity andwas bonded or adhered thereto. At this time, for making the gap betweenthe substrates approximately 4 to 5 μm, SP series produced by FineChemicals Division, Sekisui Chemical Co., Ltd. was spread with respectto the other substrate.

Regarding the density of spreading, it was controlled so that it maybe10 to 200 pieces/mm² or so. For ensuring the adhesion between the upperand the lower substrate as well as the closed space into which liquidcrystal is to be filled, sealing material was coated onto theouter-peripheral part of each substrate to a width of approximately 1mm. After the sealant was pressed, it was thermo-hardened.

A liquid material of MLC-2042 for TN produced by Merck & Co., Inc. wasinjected to prepare a liquid crystal cell. When the resulting structurewas observed using a polarizing microscope, the action that the directorgot substantially parallel with the boundary between the hydrophilicregion and the hydrophobic region occurred in the upper and the lowersubstrate. Further a state where the director was twisted 90° in thethickness direction of the liquid crystal layer was observed.

Further, the state was observed where the liquid crystal director withinthe liquid crystal cell was coming, according to the intensity of theelectric field applied, near to the electric lines of force direction ofthe electric field applied to get vertical with respect to thesubstrate.

Example 5 MVA Mode

Vertical orientation processing is executed with respect to the surfaceof the substrate in MVA mode. In this Example, for thechange-in-wettability layer, there was used a fluorine-based silicone.Also, designing was done in the way that the region occupied byhydrophobicity was equal to or greater than the region occupied byhydrophilicity, and, vertical orientation processing was executed withrespect to the resulting mass.

Also, the surface of each of the upper and the lower substrate wasdesigned to have a pattern configuration of hydrophilic property forgiving a region where the liquid crystal is inclined beforehand in aprescribed direction, or a region where the liquid crystal is likely tobe inclined in a prescribed direction, as illustrated in FIG. 3.

In this Example, isosceles-triangular regions the bottom side of that is20 μm and the height of that is 10 to 50 μm were disposed at intervalsof 10 to 50 μm. The pattern was prepared in the way that the respectiveforward ends of the isosceles-triangular regions were distributed infour directions within the substrate region. Regarding the dispositionpattern of the isosceles triangle, it was disposed alongside, and in thevicinity of, the ridge of the rib in the MVA mode and, regarding thedirection of the forward end of the isosceles triangle, it was disposedin the way that it opposed the ridge. This is because utilizing thenature that each liquid crystal molecule in the vicinity of the forwardend of the isosceles triangle gets inclined to the hydrophilic regionwhen an electric field has been applied.

Using a spin coating technique, a fluorine-based silicone describedabove was coated onto the ITO-equipped glass substrate to form arelevant film. This fluorine-based silicone film was a hydrophobic film.By performing ultraviolet-ray exposure with respect to it via theexposure mask having the photocatalyst-containing layer coated on itsuppermost surface, a hydrophilic region and hydrophobic region could bedisposed on the substrate. The fluorine-based silicone film had asufficient level of water repellency when the angle of contact withwater thereof was around 110 degrees.

Also, when exposure is performed via the substrate that has thephotocatalyst-containing layer with no light-shielding pattern, theangle of contact with water changes within a range of from approximately0 to approximately 10°, for which reason, it was observed that thewettability sufficiently changed and the film was made sufficientlyhydrophilic.

The above-described substrate was positionally aligned with anothersubstrate having disposed therein the same pattern of hydrophobicity andhydrophilicity and was bonded or adhered thereto. At this time, formaking the gap between the substrates approximately 3.5 to 4.5 μm, SPseries produced by Fine Chemicals Division, Sekisui Chemical Co., Ltd.was spread with respect to the other substrate.

Regarding the density of spreading, it was controlled so that it may be10 to 200 pieces/mm² or so. For ensuring the adhesion between the upperand the lower substrate as well as the closed space into which liquidcrystal is to be filled, sealing material was coated onto theouter-peripheral part of each substrate to a width of approximately 1mm. After the sealant was pressed, it was thermo-hardened.

A negative type liquid material of MLC-6608 produced by Merck & Co.,Inc. was injected to prepare a liquid crystal cell. When the resultingstructure was observed using a polarizing microscope, the initialorientation was obtained as the vertical orientation. Further, when avoltage was applied to the liquid crystal cell, there was observed astate where the director got inclined from the triangular hydrophilicregion to the orthogonal direction.

Further, because the acute forward end of each triangle within theregion is directed in any one of the four directions, there was observedthe divided into 4 division orientation wherein the region wasdistributed into the ones wherein the liquid crystal molecules gotinclined with their four inclinations.

1. An orientation film comprising a pattern, on its surface of a sidewhere a liquid crystal layer is contacted, that includes awater-repellent region and a hydrophilic region that is a region wherethe angle of contact with water is smaller than that in thewater-repellent region.
 2. An orientation film according to claim 1,wherein the angle of contact with water in the water-repellent region isgreater by an angle falling within a range of from 10° to 120° than thatin the hydrophilic region.
 3. An orientation film according to claim 1,wherein the angle of contact with water in the water-repellent regionfalls within a range of from 40° to 120°.
 4. An orientation filmaccording to claim 1, wherein the orientation film comprises a compoundthat has polyimide, polyamide, or organopolysiloxane as the principalchain and has as the side chain linear alkyl group, orfluorine-containing alkyl group, the number of carbons of that is from 4to 22 inclusive; and the density of the side chains in thewater-repellent region is lower than that of the side chains in thehydrophilic region.
 5. An orientation film according to claim 4,wherein, in the water-repellent region, the weight of the side chains is5% by weight or more based upon the total weight of the relevantmaterial.
 6. An orientation film according to claim 4, wherein theorganopolysiloxane is polysiloxane that contains therein a fluoroalkylgroup and is the one that is a hydrolytic condensate or co-hydrolyticcondensate of one, or two or more, kinds of silicon compounds each ofwhich is expressed by Y_(n)SiX_((4-n)) (where Y represents an alkylgroup, fluoroalkyl group, vinyl group, amino group, phenyl group, orepoxy group; X represents an alkoxyl group or halogen; and n representsan integer of from 0 to 3 inclusive.).
 7. An orientation film accordingto claim 4, wherein the polyimide is the one that is prepared by causingreaction and polymerization of at least a tetracarboxylic acid componentand a diamine component containing therein a linear alkyl group andthereby making this material a polyimide precursor containing therein alinear alkyl group and thereby imidizing the precursor.
 8. A method ofmanufacturing an orientation film, comprising an orientationfilm-forming process for forming an orientation film on a substrate, anda pattern-forming process for forming with respect to the surface of theorientation film a pattern including a water-repellent region and ahydrophilic region that is a region where the angle of contact withwater is smaller than that in the water-repellent region.
 9. A method ofmanufacturing an orientation film according to claim 8, wherein theorientation film formed on the substrate is a change-in-wettabilitylayer the wettability on whose surface changes due to the action ofphotocatalyst; and the pattern-forming process comprises: aphotocatalyst-containing layer side substrate-preparing process forpreparing a photocatalyst-containing layer side substrate that has aphotocatalyst-containing layer containing therein photocatalyst and abase material member; and a photocatalyst treatment process for, afterdisposing the photocatalyst-containing layer and thechange-in-wettability layer in the way that the gap therebetween becomes200 μm or less, radiating light energy from a prescribed direction ontothe resulting mass to thereby form a pattern, including a hydrophilicregion and a water-repellent region, with respect to the surface of thechange-in-wettability layer.
 10. A method of manufacturing anorientation film according to claim 9, wherein thephotocatalyst-containing layer side substrate comprises a base materialmember and a photocatalyst-containing layer that has formed, on thesubstrate, into a pattern configuration.
 11. A method of manufacturingan orientation film according to claim 9, wherein thephotocatalyst-containing layer side substrate that is prepared in thephotocatalyst-containing layer side substrate-preparing processcomprises a base material member, a photocatalyst-containing layerformed on the substrate, and a photocatalyst-containing layer sidelight-shielding portion formed into a patter configuration; and theradiation of the energy in the pattern-forming process is performed fromthe photocatalyst-containing layer side substrate.
 12. A method ofmanufacturing an orientation film according to claim 11, wherein, in thephotocatalyst-containing layer side substrate, thephotocatalyst-containing layer side light-shielding portion is formedinto a pattern configuration on the base material member; and, further,on the light-shielding portion, there is formed thephotocatalyst-containing layer.
 13. A method of manufacturing anorientation film according to claim 11, wherein, in thephotocatalyst-containing layer side substrate, thephotocatalyst-containing layer is formed on the base material memberand, on this photocatalyst-containing layer, thephotocatalyst-containing layer side light-shielding portion is formedinto a pattern configuration.
 14. A method of manufacturing anorientation film according to claim 9, wherein thephotocatalyst-containing layer is a layer that consists ofphotocatalyst.
 15. A method of manufacturing an orientation filmaccording to claim 14, wherein the photocatalyst-containing layer is alayer that is prepared by forming photocatalyst onto the base materialmember, as a film, by a vacuum film-making technique.
 16. A method ofmanufacturing an orientation film according to claim 9, wherein thephotocatalyst-containing layer is a layer that has photocatalyst and abinder.
 17. An orientation film-equipped substrate comprising asubstrate, and an orientation film that is formed on the substrate andthat has on its surface on a side where a liquid crystal layer iscontacted therewith a pattern including a water-repellent region and ahydrophilic region that is a region where the angle of contact withwater is smaller than that in the water-repellent region.
 18. Anorientation film-equipped substrate according to claim 17, wherein theliquid crystal layer is disposed on a side where the surface of theorientation film is located.
 19. An orientation film-equipped substrateaccording to claim 18, wherein the substrate has formed on its surface acolored layer; and on the surface of the colored layer there is formed atransparent electrode layer; and on the transparent electrode layerthere is formed the orientation film.
 20. A liquid crystal displaydevice comprising: a color filter side substrate that has a firstsubstrate, a colored layer that is formed on the first substrate, atransparent electrode layer formed on the colored layer, and anorientation film that is formed on the transparent electrode layer andthat has on its surface on a side where a liquid crystal layer iscontacted therewith a pattern including a water-repellent region and ahydrophilic region that is a region where the angle of contact withwater is smaller than that in the water-repellent region, and anopposing substrate that has a second substrate, a transparent electrodelayer formed on the second substrate, and an orientation film that isformed on the surface of the transparent electrode layer and that has onits surface on a side where a liquid crystal layer is contactedtherewith a pattern including a water-repellent region and a hydrophilicregion that is a region where the angle of contact with water is smallerthan that in the water-repellent region, whereby the orientation film ofthe color filter side substrate and the orientation film of the opposingsubstrate are disposed in the way they oppose each other; and liquidcrystal is sealed into between the two orientation films.